feat: release Colour Tools 0.1.0

2026-08-31 21:21:35 +02:00
commit 0c1fc94b58
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 node_modules/
 dist/
 release/*.zip
 release/*.zip.sha256
 coverage/
 playwright-report/
 test-results/
 *.tsbuildinfo
 .DS_Store
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@add-ideas:registry=https://git.add-ideas.de/api/packages/lotobo/npm/
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 # Changelog
 All notable changes are documented here.
 ## Unreleased
 ## 0.1.0 - 2026-08-31
 - Added a local CSS colour parser and converters for web, perceptual,
  wide-gamut and developer colour formats, including bounded batch conversion.
 - Added arbitrary RGBA layer compositing with Porter–Duff source-over,
  per-layer opacity, standard blend modes, reordering, encoded-sRGB and
  linear-light processing, and optional matte flattening.
 - Added multi-stop colour ramps with positioned stops, nine interpolation
  spaces, selectable hue routes, easing, premultiplied/straight alpha control
  and CSS/JSON export.
 - Added a large pointer and keyboard picker with alpha, exact CSS input,
  browser-native colour input, local history and optional system EyeDropper.
 - Added bounded local image decoding, coordinate and neighbourhood sampling,
  deterministic perceptual palette extraction and Web Worker fallback.
 - Added transparency-aware WCAG 2 contrast reporting and nearby passing colour
  suggestions, Delta E comparison, gamut inspection/mapping and clearly
  labelled colour-vision simulations.
 - Added harmony, tint, shade and tone generation with local named palettes,
  palette import and six design-token export formats.
 - Added the shared Toolbox shell, system/light/dark themes, responsive layouts,
  accessible navigation, nested-path deployment, offline application shell and
  deterministic static release packaging.
 - Added a GPL-3.0-or-later project licence and exact runtime dependency notices,
  including Color.js 0.7.1 under MIT.
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 # Contributing
 Thank you for improving Colour Tools. Contributions should preserve its three
 core properties: local-first processing, explicit colour semantics and a
 relocatable static build.
 ## Set up
 Use Node.js 22 or newer and npm 11 or newer.
 ```sh
 npm ci
 npm run check
 npm run test:browser
 ```
 Run `npm run dev` for the development server. Do not commit `dist/`, `release/`,
 local images, browser traces or editor secrets.
 ## Expectations
 - Keep calculations pure and serialisable where practical. Add unit tests for
  numeric boundaries, invalid input, alpha and out-of-gamut behaviour.
 - Never add telemetry, remote image processing, remote fonts or implicit
  network lookups. A feature that needs network access requires prior design
  discussion and a plainly visible, opt-in boundary.
 - Preserve values outside a target gamut until mapping is explicitly requested.
  Name the transfer curve or working light for operations where it changes the
  result.
 - Bound file bytes, decoded dimensions, worker jobs, list sizes and generated
  output. Release object URLs, workers and large buffers after use.
 - Keep all application URLs relative. Test from the nested path used by the
  Playwright server, not only `/`.
 - Ensure every pointer interaction has a keyboard route and every colour-only
  signal has a textual or structural equivalent. Use semantic controls before
  custom roles.
 - Document third-party runtime code in `THIRD_PARTY_NOTICES.md`, retain its
  exact licence in `LICENSES/`, and confirm compatibility with GPLv3 or later.
 ## Changes and review
 Keep a change focused and update `CHANGELOG.md` for user-visible behaviour.
 Include the reasoning behind colour-math choices and cite a primary standard
 where the choice is normative. Screenshots can help explain UI changes but do
 not replace browser tests.
 Before proposing a change, run `npm run check` and `npm run test:browser`.
 Tests must not contact external hosts. Security-sensitive reports should follow
 [SECURITY.md](SECURITY.md) instead of a public issue.
 Contributions are accepted under the repository's
 `GPL-3.0-or-later` licence.
@@ -0,0 +1,674 @@
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  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
 APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
 HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
 OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
 IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
 ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
  16. Limitation of Liability.
  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
 THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
 GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
 USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
 DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
 PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
 EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGES.
  17. Interpretation of Sections 15 and 16.
  If the disclaimer of warranty and limitation of liability provided
 above cannot be given local legal effect according to their terms,
 reviewing courts shall apply local law that most closely approximates
 an absolute waiver of all civil liability in connection with the
 Program, unless a warranty or assumption of liability accompanies a
 copy of the Program in return for a fee.
                     END OF TERMS AND CONDITIONS
            How to Apply These Terms to Your New Programs
  If you develop a new program, and you want it to be of the greatest
 possible use to the public, the best way to achieve this is to make it
 free software which everyone can redistribute and change under these terms.
  To do so, attach the following notices to the program.  It is safest
 to attach them to the start of each source file to most effectively
 state the exclusion of warranty; and each file should have at least
 the "copyright" line and a pointer to where the full notice is found.
    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 Also add information on how to contact you by electronic and paper mail.
  If the program does terminal interaction, make it output a short
 notice like this when it starts in an interactive mode:
    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.
 The hypothetical commands `show w' and `show c' should show the appropriate
 parts of the General Public License.  Of course, your program's commands
 might be different; for a GUI interface, you would use an "about box".
  You should also get your employer (if you work as a programmer) or school,
 if any, to sign a "copyright disclaimer" for the program, if necessary.
 For more information on this, and how to apply and follow the GNU GPL, see
 <https://www.gnu.org/licenses/>.
  The GNU General Public License does not permit incorporating your program
 into proprietary programs.  If your program is a subroutine library, you
 may consider it more useful to permit linking proprietary applications with
 the library.  If this is what you want to do, use the GNU Lesser General
 Public License instead of this License.  But first, please read
 <https://www.gnu.org/licenses/why-not-lgpl.html>.
@@ -0,0 +1,10 @@
 # Licence inventory
 Colour Tools is `GPL-3.0-or-later`; the full project licence is at `../LICENSE`.
 `THIRD_PARTY_NOTICES.md` identifies shipped runtime packages. Release
 preparation collates the exact installed licence files for every locked runtime
 package into `npm-runtime-licenses.txt`.
 `colorjs.io-MIT.txt` is retained separately because Color.js supplies the core
 standards-aligned colour conversion primitives used by the application.
@@ -0,0 +1,21 @@
 MIT License
 Copyright (c) 2021 Lea Verou, Chris Lilley
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
@@ -0,0 +1,128 @@
 # Colour Tools
 Colour Tools is a standalone, local-first browser workbench for converting,
 compositing, interpolating, sampling, comparing and organising colours. It is
 part of the
 [add·ideas Toolbox](https://git.add-ideas.de/lotobo/toolbox-portal), but every
 release also runs independently from a static HTTPS host or local preview.
 No colour, image, palette or usage event is sent to a server. Image decoding,
 pixel sampling and palette extraction happen in the browser; the application
 has no analytics, accounts, advertisements or remote lookup feature.
 ## Workspaces
 - **Convert** parses CSS colours and presents copy-ready hex, RGB, HSL, HSV,
  HWB, CMYK, Lab, LCH, OKLab, OKLCH, Display P3, Adobe RGB, ProPhoto RGB,
  Rec. 2020 and XYZ representations. Wide-gamut coordinates remain intact
  until an explicit display or gamut-mapping step. A batch converter isolates
  invalid lines instead of silently dropping them.
 - **Composite** calculates Porter–Duff source-over for an arbitrary ordered
  stack of translucent colours. Each layer has its own alpha, opacity and
  blend mode. The working-light choice makes encoded-sRGB and linear-light
  results explicit, and an optional matte produces an opaque RGB result.
 - **Steps** builds multi-stop colour ramps in perceptual, RGB or cylindrical
  colour spaces. It supports positioned stops, five hue routes, easing,
  premultiplied-alpha interpolation by default with a straight-alpha option,
  and copy-ready CSS and JSON output.
 - **Pick** provides a large keyboard- and pointer-operable HSV picker, alpha
  control, exact CSS entry, browser-native colour input, recent picks and the
  system EyeDropper API where the browser exposes it.
 - **Image** accepts one bounded local PNG, JPEG, WebP, GIF or AVIF. It samples
  an exact coordinate or a configurable average/median neighbourhood and
  extracts two to twelve perceptual palette colours in a worker when
  available.
 - **Contrast** flattens transparency against a stated canvas, reports WCAG 2
  contrast thresholds, finds a nearby passing foreground, compares colours by
  six Delta E methods, checks colour gamuts and previews four approximate
  colour-vision deficiencies.
 - **Palette** creates OKLCH harmonies, tints, shades and tones; keeps a named
  palette in local browser storage; imports common text/JSON token forms; and
  exports CSS, SCSS, JSON, Design Tokens JSON, JavaScript or CSV.
 Adding a generated or sampled colour to the palette is always explicit. The
 saved palette is device-local and can be cleared from the Palette workspace or
 by clearing site storage.
 ## Colour behaviour
 Colour Tools keeps source coordinates outside display gamuts so conversions do
 not destructively clip them. Browser previews and hex exports are mapped to
 sRGB with an explicit indicator when mapping was needed. Compositing is carried
 out in the selected sRGB working light, while interpolation defaults to OKLCH
 for perceptual spacing. See [docs/COLOUR-MATH.md](docs/COLOUR-MATH.md) for the
 formulas, bounds and terminology.
 Contrast pass/fail indicators follow WCAG 2 ratios: 3:1 for non-text UI and
 large text, 4.5:1 for normal AA text and 7:1 for normal AAA text. They are an
 engineering aid, not a complete accessibility audit; typography, state,
 context and non-colour cues still need human review.
 ## Local image handling
 Selecting an image decodes a bounded raster locally with `createImageBitmap`
 where available. The image-element fallback uses a temporary in-memory object
 URL. Decoded resources and any fallback URL are released when the image is
 replaced, removed or the workspace is closed. Palette extraction uses a
 deterministic OKLab clustering implementation and bounded sampling rather than
 uploading the image or retaining a copy. Metadata outside the decoded raster
 is not exposed or stored by the application.
 ## Browser support
 Current evergreen Firefox, Chromium and Safari are the deployment target.
 JavaScript modules, CSS custom properties, Canvas 2D and Web Workers are used.
 The EyeDropper API is progressive enhancement and only appears where a browser
 supports it. Clipboard writes, service workers and EyeDropper access may
 require HTTPS and browser permission; all core calculations work without them.
 The UI supports system, light and dark themes through the shared Toolbox shell.
 Tabs, picker controls and image sampling are keyboard operable, status changes
 use live regions, and swatches are accompanied by machine-readable colour
 values rather than relying on colour alone.
 ## Offline application shell
 Production builds include a relative-scope web app manifest and a
 subpath-aware service worker. After one successful load, the worker caches the
 application shell and same-origin built assets, uses network-first navigation
 with a cached fallback, serves cached static resources where possible and
 removes obsolete cache versions. Service-worker support is optional; colour
 operations never depend on a network connection.
 ## Development
 Requirements: Node.js 22 or newer and npm 11 or newer.
 ```sh
 npm ci
 npm run check
 npm run test:browser
 npm run dev
 ```
 Vite uses `base: './'`, so `dist/` is relocatable to `/` or a nested Toolbox
 path. `toolbox-check` validates standalone and contextual operation.
 The main implementation layers are described in
 [docs/ARCHITECTURE.md](docs/ARCHITECTURE.md). Contributions should follow
 [CONTRIBUTING.md](CONTRIBUTING.md); please report security concerns according
 to [SECURITY.md](SECURITY.md).
 ## Release
 ```sh
 npm run release:artifact
 ```
 This command checks the manifest, types, lint, formatting, unit tests,
 production build, Toolbox contract and browser workflows, then creates a
 deterministic `release/colour-tools-0.1.0.zip` and matching SHA-256 sidecar.
 The archive is a ready-to-host static application and contains project and
 third-party licence notices.
 ## Licence
 Colour Tools is free software under `GPL-3.0-or-later`. See
 [LICENSE](LICENSE). Runtime dependencies retain their respective licences; see
 [THIRD_PARTY_NOTICES.md](THIRD_PARTY_NOTICES.md).
@@ -0,0 +1,50 @@
 # Security policy
 ## Supported versions
 Security fixes are made on the current release line. Users should update to the
 latest published tag and verify the release ZIP against its `.sha256` sidecar.
 ## Reporting a vulnerability
 Please report a suspected vulnerability privately to the repository owner via
 the contact channel shown on the
 [Gitea profile](https://git.add-ideas.de/lotobo) or a private Gitea message. Do
 not include private images, access tokens, unpublished exploit details or other
 sensitive material in a public issue.
 Include the affected version, browser and operating system; a minimal local
 reproduction; the expected impact; and whether the issue requires a crafted
 image, palette or colour string. You should receive acknowledgement within
 seven days. Coordinated disclosure is appreciated while a fix and release are
 prepared.
 ## Security model
 Colour Tools is a static browser application. It has no application backend,
 account system, analytics endpoint or image-upload endpoint. All selected image
 bytes are decoded and processed locally. Saved palette entries use browser
 storage for the current origin. Clipboard, file picker, download and EyeDropper
 actions happen only after a user gesture and remain governed by browser
 permissions.
 File processing is deliberately bounded by encoded byte size, decoded pixel
 count and dimensions. Image palette extraction samples a bounded number of
 pixels and can run in a disposable worker. Object URLs and worker jobs are
 cancelled or released when replaced. Input is displayed as text or parsed by
 typed colour/image APIs; it is not evaluated as script or inserted as trusted
 HTML.
 Production hosts should serve the headers in
 [docs/PRIVACY-SECURITY.md](docs/PRIVACY-SECURITY.md), use HTTPS, keep MIME types
 correct, disable content sniffing and avoid injecting third-party scripts. A
 host can still observe ordinary HTTP metadata for the initial static-file
 request; “local-first” describes application data processing, not anonymity
 from the static host.
 ## Out of scope
 Colour rendering differences between conforming browser/OS colour-management
 pipelines are not vulnerabilities by themselves. Likewise, an approximate
 colour-vision simulation is an educational preview, not a medical diagnosis or
 a complete accessibility guarantee.
@@ -0,0 +1,31 @@
 # Corresponding source and provenance
 The corresponding source for Colour Tools 0.1.0 is:
 https://git.add-ideas.de/lotobo/colour-tools/src/tag/v0.1.0
 Build that tag with Node.js 22 and the exact dependency graph recorded in
 `package-lock.json`:
 ```sh
 npm ci
 npm run release:artifact
 ```
 The generated JavaScript and CSS bundles are not the preferred form for
 modification. No runtime code is loaded from a CDN. The production ZIP contains
 this source pointer, the application licence, the dependency licence inventory,
 and the applicable third-party notices.
 ## Implementation provenance
 - The application is original project code and uses the shared Toolbox SDK
  packages at version 0.2.3 for its manifest contract, shell, and build checks.
 - Colour conversion and adaptation use Color.js 0.7.1. Its MIT licence is
  reproduced in `LICENSES/colorjs.io-MIT.txt`.
 - The compositing, interpolation, palette, image-sampling, contrast, comparison,
  gamut, and colour-vision utilities in `src/colour` and `src/palette` were
  implemented for this project.
 - CSS Color 4 and WCAG 2.2 were used as public technical specifications. No
  source code or branded assets were copied from the example websites that
  informed the feature list.
@@ -0,0 +1,25 @@
 # Third-party notices
 Release preparation collates licence files for the exact locked runtime
 packages into `LICENSES/npm-runtime-licenses.txt` inside the static artifact.
 | Package                          | Version | Licence    | Role                                 | Source                                      |
 | -------------------------------- | ------- | ---------- | ------------------------------------ | ------------------------------------------- |
 | `@add-ideas/toolbox-contract`    | 0.2.3   | Apache-2.0 | manifest and context contract        | https://git.add-ideas.de/lotobo/toolbox-sdk |
 | `@add-ideas/toolbox-shell-react` | 0.2.3   | Apache-2.0 | shared shell, theme and actions      | https://git.add-ideas.de/lotobo/toolbox-sdk |
 | `colorjs.io`                     | 0.7.1   | MIT        | parsing, conversion and colour maths | https://github.com/color-js/color.js        |
 | `react`                          | 19.2.8  | MIT        | application UI                       | https://github.com/facebook/react           |
 | `react-dom`                      | 19.2.8  | MIT        | browser rendering                    | https://github.com/facebook/react           |
 `scheduler` 0.27.0, distributed by the React project under MIT, is the only
 transitive runtime package. Development-only packages build and test the
 source but are not shipped as runtime modules.
 The exact Color.js notice is retained at
 `LICENSES/colorjs.io-MIT.txt`. Apache-2.0 and MIT texts from all installed
 runtime packages are reproduced by the deterministic release-preparation step.
 CSS Color, CSS Compositing and Blending, WCAG and the linked web utilities that
 informed the product requirements are specification or research references
 only. Their source code, artwork and documentation wording are not bundled or
 copied into Colour Tools.
@@ -0,0 +1,19 @@
 # Accessibility notes
 Colour Tools treats colour as data as well as appearance. Swatches are paired
 with textual values, gamut/contrast status uses text and symbols in addition to
 hue, and generated palettes remain usable without visually distinguishing
 every swatch.
 Workspace navigation uses tabs with selected state and arrow/Home/End keyboard
 navigation. Native inputs and labelled controls are preferred. The large picker
 supports arrow-key adjustment and announces its saturation and brightness;
 image sampling supports numeric coordinates and keyboard movement in addition
 to pointer selection. Calculation and file statuses use live regions without
 clearing the last valid result while a user is typing.
 The shared Toolbox shell provides system, light and dark themes. Focus rings,
 touch targets, reflow and text contrast should be checked in all themes and at
 400% zoom. A WCAG contrast result is not itself proof that the complete
 interface conforms: test keyboard order, names/roles/values, error recovery,
 high contrast modes, reduced motion and screen-reader output in context.
@@ -0,0 +1,69 @@
 # Architecture
 Colour Tools is a client-only React application built as relocatable static
 files. The UI and calculation engine are intentionally separated so colour
 operations can be tested without a browser and UI state can keep showing the
 last valid result while an input is incomplete.
 ## Layers
 1. `src/colour/` is the serialisable colour domain. It parses and formats
   colours, converts gamuts, composites layers, interpolates stops, evaluates
   contrast and Delta E, simulates colour-vision deficiencies, and builds or
   exports palettes. Its public API is re-exported from `src/colour/index.ts`.
 2. `src/palette/` contains browser-independent raster bounds, sampling and
   deterministic OKLab clustering. `src/workers/palette.worker.ts` exposes the
   expensive extraction path to a dedicated worker.
 3. `src/components/` contains the seven workspaces and shared accessible
   controls. Workspace selection is represented by a URL fragment, so a view
   can be bookmarked without router or server support.
 4. `src/hooks/` owns bounded device-local UI persistence. Image bytes are not
   stored there.
 5. `src/toolbox/` contains the checked manifest identity. The shared Toolbox
   shell supplies navigation, contextual actions and theme behaviour without
   changing the standalone application domain.
 ## Colour values
 The engine's `ColourValue` is a plain object: colour-space identifier, three
 numeric coordinates and alpha. It deliberately carries coordinates that may
 sit outside a display gamut. Color.js 0.7.1 supplies standards-aligned parsing
 and conversion primitives; Colour Tools wraps these in typed, bounded domain
 operations and stable UI formats.
 Browser preview is a separate operation. It maps a value to sRGB and reports
 whether mapping occurred. This keeps display limitations from mutating the
 source colour used by later conversions or comparisons.
 ## Raster pipeline
 The image picker validates the selected file before decode, rejects excessive
 bytes/dimensions/pixels, then draws the decoded image to a same-origin in-memory
 Canvas 2D surface. Sampling reads a bounded neighbourhood. Palette extraction
 subsamples deterministically, converts points to OKLab and clusters them with a
 fixed initialization and iteration bound. The worker client can fall back to
 the same pure function when workers are unavailable.
 Temporary object URLs are revoked and outstanding extraction is aborted when an
 image is replaced or removed. No image or extracted palette is transmitted.
 ## Build and deployment
 Vite builds with a relative base. `scripts/generate-toolbox-manifest.mjs`
 checks package, application and Toolbox versions plus immutable source
 identity. `scripts/prepare-release-files.mjs` places project documentation and
 the exact installed runtime licence inventory beside the executable app.
 The service worker is relative-scope and deployment-subpath aware. It is
 progressive enhancement: the app remains usable when registration is rejected.
 The deterministic packager rejects symbolic links, source maps, secret-like
 filenames and root-absolute asset references before creating the release ZIP
 and SHA-256 sidecar.
 ## Testing boundaries
 Unit tests cover parsing, numerical operations, invalid inputs, raster bounds,
 sampling and palette determinism. Browser smoke tests run the production build
 under a restrictive policy at `/deep/nested/colour/`, exercise all major
 workspaces and fail on uncaught errors or external network requests. The
 Toolbox contract checker validates the static artifact independently.
@@ -0,0 +1,94 @@
 # Colour mathematics and terminology
 This document records the choices that materially change a result. It is not a
 replacement for CSS Color, Compositing and Blending, or WCAG.
 ## Parsing and conversion
 The parser accepts CSS colour syntax supported by the installed Color.js
 version, including hex and named colours; `rgb()`, `hsl()`, `hwb()`, Lab/LCH
 and OKLab/OKLCH functions; and registered `color()` spaces. Conversion keeps
 finite coordinates outside a target gamut. Hex and ordinary browser sRGB
 previews require mapping; the UI labels when this happened.
 The converter exposes device-oriented and mathematical representations, but a
 numeric tuple is meaningful only with its named colour space, white point,
 transfer curve and alpha convention. CMYK output is a convenient mathematical
 conversion, not a printer ICC separation or proof.
 ## Alpha compositing
 For a source colour over a backdrop, with straight alpha `αs` and `αb`, output
 alpha is:
 ```text
 αo = αs + αb × (1 − αs)
 ```
 For each premultiplied channel under normal source-over:
 ```text
 Co = Cs × αs + Cb × αb × (1 − αs)
 co = Co / αo                         when αo > 0
 ```
 Layers are accumulated from the bottom upward even though the editor displays
 the top layer first. Layer opacity multiplies the colour's own alpha. Blend
 modes are applied before source-over using the model in CSS Compositing and
 Blending.
 “Encoded sRGB” applies the operation directly to sRGB-encoded channel values,
 matching many quick web calculators. “Linear-light sRGB” first removes the
 sRGB transfer curve and is generally the physically meaningful choice for
 mixing emitted light. The two results are expected to differ.
 ## Interpolation
 A ramp samples its first and last stop and distributes missing positions like a
 CSS gradient. Each segment is interpolated in the selected space with the
 chosen easing. Cylindrical spaces need an explicit hue route: shorter, longer,
 increasing, decreasing or raw. The default premultiplies colour components by
 alpha before mixing and unpremultiplies afterwards, preventing hidden channels
 inside a transparent endpoint from tinting the ramp. A straight-alpha toggle
 is available for intentionally reproducing that model. OKLCH is the UI default
 because equal numeric progress tends to look more even than encoded RGB; it
 does not guarantee that every intermediate colour lies in a display gamut.
 ## Gamut mapping
 An in-gamut check does not modify the colour. Display mapping uses an OKLCH
 chroma-reduction method by default; channel clipping is available at the engine
 boundary where explicitly selected. The result includes Delta E OK from the
 source so callers can quantify the change. A browser preview is always mapped
 to sRGB because CSS support and physical displays differ.
 ## Contrast and transparency
 Relative luminance and WCAG 2 contrast are evaluated after translucent
 foreground/background colours are composited over the stated canvas (white by
 default). The ratio is:
 ```text
 (Llighter + 0.05) / (Ldarker + 0.05)
 ```
 The UI reports 3:1, 4.5:1 and 7:1 thresholds and searches for a nearby lighter
 or darker passing foreground. A mathematical pass is only one part of an
 accessibility review; font size/weight, focus states, disabled controls,
 non-colour cues and actual display conditions remain relevant.
 ## Perceptual difference and simulations
 Delta E 76, CMC, CIEDE2000, Delta E OK, ITP and Jz answer different historical
 or application needs; values from different formulas are not interchangeable.
 The colour-vision previews apply bounded matrices in linear sRGB and expose a
 severity control. They are approximations for interface review, not a model of
 every observer and not medical advice.
 ## Palette extraction
 The raster extractor ignores sufficiently transparent pixels, converts bounded
 samples to OKLab and clusters them deterministically. Reported coverage is the
 share of accepted samples assigned to a cluster, not an exact segmentation of
 every source pixel. Small antialiased regions and colour-managed decoding can
 therefore influence the result.
@@ -0,0 +1,60 @@
 # Privacy, security and deployment
 ## Data flow
 Colour input, saved palette entries, selected image bytes, decoded pixels and
 generated exports stay in the browser. The application does not issue API
 requests, load remote fonts, submit analytics or resolve remote colour
 references. A saved palette belongs to the current browser origin and is
 stored until the user clears it or browser storage is removed. Images are
 in-memory only.
 The static host still receives ordinary requests for HTML, JavaScript, CSS,
 icons and worker files on initial load and revalidation. Host logs, reverse
 proxy logs and browser extension behaviour are outside the application's local
 processing boundary.
 ## Recommended headers
 Serve the static artifact over HTTPS and apply a policy equivalent to:
 ```text
 Content-Security-Policy: default-src 'self'; base-uri 'self'; object-src 'none'; frame-ancestors 'none'; form-action 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; connect-src 'self'; worker-src 'self' blob:; manifest-src 'self'
 Cross-Origin-Opener-Policy: same-origin
 Cross-Origin-Resource-Policy: same-origin
 Permissions-Policy: camera=(), microphone=(), geolocation=(), usb=(), payment=()
 Referrer-Policy: no-referrer
 X-Content-Type-Options: nosniff
 ```
 The shared Toolbox shell uses inline style properties for colour previews, so
 `style-src 'unsafe-inline'` is currently required. Do not add
 `script-src 'unsafe-inline'` or third-party script origins. `blob:` is required
 for local image object URLs and may be used for a worker fallback.
 Serve `.js` as `text/javascript`, `.json` as `application/json`, `.webmanifest`
 as `application/manifest+json`, and `.svg` as `image/svg+xml`. Hashed assets may
 use a long immutable cache lifetime; keep `index.html`, `sw.js` and
 `toolbox-app.json` on revalidation/no-cache so releases update predictably.
 ## Reverse-proxy example
 For an nginx deployment rooted at `/apps/colour/`, use `try_files` only to
 resolve actual static files and the directory index; do not rewrite missing
 asset paths to HTML. The application itself uses relative paths and needs no
 server-side router. Keep the `sw.js` scope at the application directory.
 If the app is assembled into toolbox-portal, use the portal's release lock and
 assembly process instead of unpacking files into an existing live directory.
 Verify the ZIP against its SHA-256 sidecar before assembly.
 ## File limits and cleanup
 The image picker enforces encoded-byte, dimension and decoded-pixel limits
 before expensive processing. Sampling radius and palette colour counts are
 bounded. Object URLs, decoded buffers and worker requests are released or
 cancelled when replaced. Browsers and image decoders remain security-sensitive
 dependencies, so deploy current supported browser versions and publish patched
 application releases promptly.
 See [SECURITY.md](../SECURITY.md) for private reporting instructions.
@@ -0,0 +1,40 @@
 import js from "@eslint/js";
 import globals from "globals";
 import reactHooks from "eslint-plugin-react-hooks";
 import reactRefresh from "eslint-plugin-react-refresh";
 import tseslint from "typescript-eslint";
 export default tseslint.config(
  {
    ignores: [
      "dist",
      "release",
      "coverage",
      "test-results",
      "playwright-report",
    ],
  },
  {
    extends: [js.configs.recommended, ...tseslint.configs.recommended],
    files: ["**/*.{ts,tsx}"],
    languageOptions: {
      ecmaVersion: 2023,
      globals: { ...globals.browser, ...globals.worker },
    },
    plugins: {
      "react-hooks": reactHooks,
      "react-refresh": reactRefresh,
    },
    rules: {
      ...reactHooks.configs.recommended.rules,
      "react-refresh/only-export-components": [
        "warn",
        { allowConstantExport: true },
      ],
    },
  },
  {
    files: ["scripts/**/*.mjs", "playwright.config.ts"],
    languageOptions: { globals: globals.node },
  },
 );
@@ -0,0 +1,19 @@
 <!doctype html>
 <html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta
      name="description"
      content="Convert, composite, compare and build colours locally in your browser."
    />
    <link rel="icon" type="image/svg+xml" href="./favicon.svg" />
    <link rel="manifest" href="./manifest.webmanifest" />
    <meta name="theme-color" content="#2d2859" />
    <title>Colour Tools</title>
  </head>
  <body>
    <div id="root"></div>
    <script type="module" src="./src/main.tsx"></script>
  </body>
 </html>
@@ -0,0 +1,72 @@
 {
  "name": "colour-tools",
  "version": "0.1.0",
  "description": "Convert, composite, compare and build colours locally in the browser.",
  "license": "GPL-3.0-or-later",
  "author": "Albrecht Degering",
  "repository": {
    "type": "git",
    "url": "git+https://git.add-ideas.de/lotobo/colour-tools.git"
  },
  "homepage": "https://git.add-ideas.de/lotobo/colour-tools",
  "bugs": {
    "url": "https://git.add-ideas.de/lotobo/colour-tools/issues"
  },
  "private": true,
  "type": "module",
  "engines": {
    "node": ">=22"
  },
  "scripts": {
    "predev": "npm run manifest:generate",
    "dev": "vite",
    "prebuild": "npm run release:prepare && npm run manifest:generate",
    "build": "tsc -b && vite build",
    "preview": "vite preview",
    "typecheck": "tsc -b --pretty false",
    "lint": "eslint . --max-warnings=0",
    "format": "prettier --write .",
    "format:check": "prettier --check .",
    "test": "vitest run",
    "test:watch": "vitest",
    "test:browser": "playwright test",
    "manifest:generate": "node scripts/generate-toolbox-manifest.mjs",
    "manifest:check": "node scripts/generate-toolbox-manifest.mjs --check",
    "release:prepare": "node scripts/prepare-release-files.mjs",
    "toolbox:check": "toolbox-check dist",
    "package:release": "node scripts/package-release.mjs",
    "check": "npm run manifest:check && npm run typecheck && npm run lint && npm run format:check && npm run test && npm run build && npm run toolbox:check",
    "release:artifact": "npm run check && npm run test:browser && npm run package:release -- --force"
  },
  "dependencies": {
    "@add-ideas/toolbox-contract": "0.2.3",
    "@add-ideas/toolbox-shell-react": "0.2.3",
    "colorjs.io": "0.7.1",
    "react": "19.2.8",
    "react-dom": "19.2.8"
  },
  "devDependencies": {
    "@add-ideas/toolbox-testkit": "0.2.3",
    "@eslint/js": "10.0.1",
    "@playwright/test": "1.62.1",
    "@testing-library/jest-dom": "6.9.1",
    "@testing-library/react": "16.3.2",
    "@testing-library/user-event": "14.6.1",
    "@types/node": "25.9.5",
    "@types/react": "19.2.17",
    "@types/react-dom": "19.2.5",
    "@vitejs/plugin-react": "6.0.3",
    "eslint": "10.7.0",
    "eslint-plugin-react-hooks": "7.1.1",
    "eslint-plugin-react-refresh": "0.5.2",
    "fast-check": "4.9.0",
    "globals": "17.7.0",
    "jsdom": "29.1.1",
    "prettier": "3.9.5",
    "typescript": "6.0.3",
    "typescript-eslint": "8.64.0",
    "vite": "8.2.2",
    "vitest": "4.1.11"
  },
  "packageManager": "npm@11.17.0"
 }
@@ -0,0 +1,24 @@
 import { defineConfig, devices } from "@playwright/test";
 export default defineConfig({
  testDir: "./tests/browser",
  fullyParallel: false,
  workers: 1,
  timeout: 120_000,
  expect: { timeout: 10_000 },
  reporter: [["list"]],
  use: {
    baseURL: "http://127.0.0.1:4173",
    trace: "retain-on-failure",
  },
  webServer: {
    command: "npm run build && node scripts/serve-test.mjs",
    url: "http://127.0.0.1:4173",
    reuseExistingServer: !process.env.CI,
    timeout: 180_000,
  },
  projects: [
    { name: "chromium", use: { ...devices["Desktop Chrome"] } },
    { name: "firefox", use: { ...devices["Desktop Firefox"] } },
  ],
 });
@@ -0,0 +1,30 @@
 # Changelog
 All notable changes are documented here.
 ## Unreleased
 ## 0.1.0 - 2026-08-31
 - Added a local CSS colour parser and converters for web, perceptual,
  wide-gamut and developer colour formats, including bounded batch conversion.
 - Added arbitrary RGBA layer compositing with Porter–Duff source-over,
  per-layer opacity, standard blend modes, reordering, encoded-sRGB and
  linear-light processing, and optional matte flattening.
 - Added multi-stop colour ramps with positioned stops, nine interpolation
  spaces, selectable hue routes, easing, premultiplied/straight alpha control
  and CSS/JSON export.
 - Added a large pointer and keyboard picker with alpha, exact CSS input,
  browser-native colour input, local history and optional system EyeDropper.
 - Added bounded local image decoding, coordinate and neighbourhood sampling,
  deterministic perceptual palette extraction and Web Worker fallback.
 - Added transparency-aware WCAG 2 contrast reporting and nearby passing colour
  suggestions, Delta E comparison, gamut inspection/mapping and clearly
  labelled colour-vision simulations.
 - Added harmony, tint, shade and tone generation with local named palettes,
  palette import and six design-token export formats.
 - Added the shared Toolbox shell, system/light/dark themes, responsive layouts,
  accessible navigation, nested-path deployment, offline application shell and
  deterministic static release packaging.
 - Added a GPL-3.0-or-later project licence and exact runtime dependency notices,
  including Color.js 0.7.1 under MIT.
@@ -0,0 +1,52 @@
 # Contributing
 Thank you for improving Colour Tools. Contributions should preserve its three
 core properties: local-first processing, explicit colour semantics and a
 relocatable static build.
 ## Set up
 Use Node.js 22 or newer and npm 11 or newer.
 ```sh
 npm ci
 npm run check
 npm run test:browser
 ```
 Run `npm run dev` for the development server. Do not commit `dist/`, `release/`,
 local images, browser traces or editor secrets.
 ## Expectations
 - Keep calculations pure and serialisable where practical. Add unit tests for
  numeric boundaries, invalid input, alpha and out-of-gamut behaviour.
 - Never add telemetry, remote image processing, remote fonts or implicit
  network lookups. A feature that needs network access requires prior design
  discussion and a plainly visible, opt-in boundary.
 - Preserve values outside a target gamut until mapping is explicitly requested.
  Name the transfer curve or working light for operations where it changes the
  result.
 - Bound file bytes, decoded dimensions, worker jobs, list sizes and generated
  output. Release object URLs, workers and large buffers after use.
 - Keep all application URLs relative. Test from the nested path used by the
  Playwright server, not only `/`.
 - Ensure every pointer interaction has a keyboard route and every colour-only
  signal has a textual or structural equivalent. Use semantic controls before
  custom roles.
 - Document third-party runtime code in `THIRD_PARTY_NOTICES.md`, retain its
  exact licence in `LICENSES/`, and confirm compatibility with GPLv3 or later.
 ## Changes and review
 Keep a change focused and update `CHANGELOG.md` for user-visible behaviour.
 Include the reasoning behind colour-math choices and cite a primary standard
 where the choice is normative. Screenshots can help explain UI changes but do
 not replace browser tests.
 Before proposing a change, run `npm run check` and `npm run test:browser`.
 Tests must not contact external hosts. Security-sensitive reports should follow
 [SECURITY.md](SECURITY.md) instead of a public issue.
 Contributions are accepted under the repository's
 `GPL-3.0-or-later` licence.
@@ -0,0 +1,674 @@
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 available, or (2) arrange to deprive yourself of the benefit of the
 patent license for this particular work, or (3) arrange, in a manner
 consistent with the requirements of this License, to extend the patent
 license to downstream recipients.  "Knowingly relying" means you have
 actual knowledge that, but for the patent license, your conveying the
 covered work in a country, or your recipient's use of the covered work
 in a country, would infringe one or more identifiable patents in that
 country that you have reason to believe are valid.
  If, pursuant to or in connection with a single transaction or
 arrangement, you convey, or propagate by procuring conveyance of, a
 covered work, and grant a patent license to some of the parties
 receiving the covered work authorizing them to use, propagate, modify
 or convey a specific copy of the covered work, then the patent license
 you grant is automatically extended to all recipients of the covered
 work and works based on it.
  A patent license is "discriminatory" if it does not include within
 the scope of its coverage, prohibits the exercise of, or is
 conditioned on the non-exercise of one or more of the rights that are
 specifically granted under this License.  You may not convey a covered
 work if you are a party to an arrangement with a third party that is
 in the business of distributing software, under which you make payment
 to the third party based on the extent of your activity of conveying
 the work, and under which the third party grants, to any of the
 parties who would receive the covered work from you, a discriminatory
 patent license (a) in connection with copies of the covered work
 conveyed by you (or copies made from those copies), or (b) primarily
 for and in connection with specific products or compilations that
 contain the covered work, unless you entered into that arrangement,
 or that patent license was granted, prior to 28 March 2007.
  Nothing in this License shall be construed as excluding or limiting
 any implied license or other defenses to infringement that may
 otherwise be available to you under applicable patent law.
  12. No Surrender of Others' Freedom.
  If conditions are imposed on you (whether by court order, agreement or
 otherwise) that contradict the conditions of this License, they do not
 excuse you from the conditions of this License.  If you cannot convey a
 covered work so as to satisfy simultaneously your obligations under this
 License and any other pertinent obligations, then as a consequence you may
 not convey it at all.  For example, if you agree to terms that obligate you
 to collect a royalty for further conveying from those to whom you convey
 the Program, the only way you could satisfy both those terms and this
 License would be to refrain entirely from conveying the Program.
  13. Use with the GNU Affero General Public License.
  Notwithstanding any other provision of this License, you have
 permission to link or combine any covered work with a work licensed
 under version 3 of the GNU Affero General Public License into a single
 combined work, and to convey the resulting work.  The terms of this
 License will continue to apply to the part which is the covered work,
 but the special requirements of the GNU Affero General Public License,
 section 13, concerning interaction through a network will apply to the
 combination as such.
  14. Revised Versions of this License.
  The Free Software Foundation may publish revised and/or new versions of
 the GNU General Public License from time to time.  Such new versions will
 be similar in spirit to the present version, but may differ in detail to
 address new problems or concerns.
  Each version is given a distinguishing version number.  If the
 Program specifies that a certain numbered version of the GNU General
 Public License "or any later version" applies to it, you have the
 option of following the terms and conditions either of that numbered
 version or of any later version published by the Free Software
 Foundation.  If the Program does not specify a version number of the
 GNU General Public License, you may choose any version ever published
 by the Free Software Foundation.
  If the Program specifies that a proxy can decide which future
 versions of the GNU General Public License can be used, that proxy's
 public statement of acceptance of a version permanently authorizes you
 to choose that version for the Program.
  Later license versions may give you additional or different
 permissions.  However, no additional obligations are imposed on any
 author or copyright holder as a result of your choosing to follow a
 later version.
  15. Disclaimer of Warranty.
  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
 APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
 HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
 OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
 IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
 ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
  16. Limitation of Liability.
  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
 THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
 GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
 USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
 DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
 PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
 EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGES.
  17. Interpretation of Sections 15 and 16.
  If the disclaimer of warranty and limitation of liability provided
 above cannot be given local legal effect according to their terms,
 reviewing courts shall apply local law that most closely approximates
 an absolute waiver of all civil liability in connection with the
 Program, unless a warranty or assumption of liability accompanies a
 copy of the Program in return for a fee.
                     END OF TERMS AND CONDITIONS
            How to Apply These Terms to Your New Programs
  If you develop a new program, and you want it to be of the greatest
 possible use to the public, the best way to achieve this is to make it
 free software which everyone can redistribute and change under these terms.
  To do so, attach the following notices to the program.  It is safest
 to attach them to the start of each source file to most effectively
 state the exclusion of warranty; and each file should have at least
 the "copyright" line and a pointer to where the full notice is found.
    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 Also add information on how to contact you by electronic and paper mail.
  If the program does terminal interaction, make it output a short
 notice like this when it starts in an interactive mode:
    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.
 The hypothetical commands `show w' and `show c' should show the appropriate
 parts of the General Public License.  Of course, your program's commands
 might be different; for a GUI interface, you would use an "about box".
  You should also get your employer (if you work as a programmer) or school,
 if any, to sign a "copyright disclaimer" for the program, if necessary.
 For more information on this, and how to apply and follow the GNU GPL, see
 <https://www.gnu.org/licenses/>.
  The GNU General Public License does not permit incorporating your program
 into proprietary programs.  If your program is a subroutine library, you
 may consider it more useful to permit linking proprietary applications with
 the library.  If this is what you want to do, use the GNU Lesser General
 Public License instead of this License.  But first, please read
 <https://www.gnu.org/licenses/why-not-lgpl.html>.
@@ -0,0 +1,10 @@
 # Licence inventory
 Colour Tools is `GPL-3.0-or-later`; the full project licence is at `../LICENSE`.
 `THIRD_PARTY_NOTICES.md` identifies shipped runtime packages. Release
 preparation collates the exact installed licence files for every locked runtime
 package into `npm-runtime-licenses.txt`.
 `colorjs.io-MIT.txt` is retained separately because Color.js supplies the core
 standards-aligned colour conversion primitives used by the application.
@@ -0,0 +1,21 @@
 MIT License
 Copyright (c) 2021 Lea Verou, Chris Lilley
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
@@ -0,0 +1,514 @@
 ==============================================================================
@add-ideas/toolbox-contract@0.2.3
 Declared licence: Apache-2.0
 Installed from: node_modules/@add-ideas/toolbox-contract
 ==============================================================================
 --- LICENSE ---
                                 Apache License
                           Version 2.0, January 2004
                        http://www.apache.org/licenses/
   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
   1. Definitions.
      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.
      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.
      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the
      outstanding shares, or (iii) beneficial ownership of such entity.
      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.
      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.
      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.
      "Work" shall mean the work of authorship, whether in Source or
      Object form, made available under the License, as indicated by a
      copyright notice that is included in or attached to the work
      (an example is provided in the Appendix below).
      "Derivative Works" shall mean any work, whether in Source or Object
      form, that is based on (or derived from) the Work and for which the
      editorial revisions, annotations, elaborations, or other modifications
      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.
      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions
      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent
      to the Licensor or its representatives, including but not limited to
      communication on electronic mailing lists, source code control systems,
      and issue tracking systems that are managed by, or on behalf of, the
      Licensor for the purpose of discussing and improving the Work, but
      excluding communication that is conspicuously marked or otherwise
      designated in writing by the copyright owner as "Not a Contribution."
      "Contributor" shall mean Licensor and any individual or Legal Entity
      on behalf of whom a Contribution has been received by Licensor and
      subsequently incorporated within the Work.
   2. Grant of Copyright License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.
   3. Grant of Patent License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their
      Contribution(s) alone or by combination of their Contribution(s)
      with the Work to which such Contribution(s) was submitted. If You
      institute patent litigation against any entity (including a
      cross-claim or counterclaim in a lawsuit) alleging that the Work
      or a Contribution incorporated within the Work constitutes direct
      or contributory patent infringement, then any patent licenses
      granted to You under this License for that Work shall terminate
      as of the date such litigation is filed.
   4. Redistribution. You may reproduce and distribute copies of the
      Work or Derivative Works thereof in any medium, with or without
      modifications, and in Source or Object form, provided that You
      meet the following conditions:
      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and
      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and
      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and
          attribution notices from the Source form of the Work,
          excluding those notices that do not pertain to any part of
          the Derivative Works; and
      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed
          as part of the Derivative Works; within the Source form or
          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.
      You may add Your own copyright statement to Your modifications and
      may provide additional or different license terms and conditions
      for use, reproduction, or distribution of Your modifications, or
      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.
   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of
      this License, without any additional terms or conditions.
      Notwithstanding the above, nothing herein shall supersede or modify
      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.
   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.
   7. Disclaimer of Warranty. Unless required by applicable law or
      agreed to in writing, Licensor provides the Work (and each
      Contributor provides its Contributions) on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
      implied, including, without limitation, any warranties or conditions
      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
      PARTICULAR PURPOSE. You are solely responsible for determining the
      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.
   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly
      negligent acts) or agreed to in writing, shall any Contributor be
      liable to You for damages, including any direct, indirect, special,
      incidental, or consequential damages of any character arising as a
      result of this License or out of the use or inability to use the
      Work (including but not limited to damages for loss of goodwill,
      work stoppage, computer failure or malfunction, or any and all
      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.
   9. Accepting Warranty or Additional Liability. While redistributing
      the Work or Derivative Works thereof, You may choose to offer,
      and charge a fee for, acceptance of support, warranty, indemnity,
      or other liability obligations and/or rights consistent with this
      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.
   END OF TERMS AND CONDITIONS
   APPENDIX: How to apply the Apache License to your work.
      Copyright 2026 ADD Ideas
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at
          http://www.apache.org/licenses/LICENSE-2.0
      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.
 ==============================================================================
@add-ideas/toolbox-shell-react@0.2.3
 Declared licence: Apache-2.0
 Installed from: node_modules/@add-ideas/toolbox-shell-react
 ==============================================================================
 --- LICENSE ---
                                 Apache License
                           Version 2.0, January 2004
                        http://www.apache.org/licenses/
   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
   1. Definitions.
      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.
      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.
      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the
      outstanding shares, or (iii) beneficial ownership of such entity.
      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.
      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.
      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.
      "Work" shall mean the work of authorship, whether in Source or
      Object form, made available under the License, as indicated by a
      copyright notice that is included in or attached to the work
      (an example is provided in the Appendix below).
      "Derivative Works" shall mean any work, whether in Source or Object
      form, that is based on (or derived from) the Work and for which the
      editorial revisions, annotations, elaborations, or other modifications
      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.
      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions
      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent
      to the Licensor or its representatives, including but not limited to
      communication on electronic mailing lists, source code control systems,
      and issue tracking systems that are managed by, or on behalf of, the
      Licensor for the purpose of discussing and improving the Work, but
      excluding communication that is conspicuously marked or otherwise
      designated in writing by the copyright owner as "Not a Contribution."
      "Contributor" shall mean Licensor and any individual or Legal Entity
      on behalf of whom a Contribution has been received by Licensor and
      subsequently incorporated within the Work.
   2. Grant of Copyright License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.
   3. Grant of Patent License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their
      Contribution(s) alone or by combination of their Contribution(s)
      with the Work to which such Contribution(s) was submitted. If You
      institute patent litigation against any entity (including a
      cross-claim or counterclaim in a lawsuit) alleging that the Work
      or a Contribution incorporated within the Work constitutes direct
      or contributory patent infringement, then any patent licenses
      granted to You under this License for that Work shall terminate
      as of the date such litigation is filed.
   4. Redistribution. You may reproduce and distribute copies of the
      Work or Derivative Works thereof in any medium, with or without
      modifications, and in Source or Object form, provided that You
      meet the following conditions:
      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and
      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and
      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and
          attribution notices from the Source form of the Work,
          excluding those notices that do not pertain to any part of
          the Derivative Works; and
      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed
          as part of the Derivative Works; within the Source form or
          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.
      You may add Your own copyright statement to Your modifications and
      may provide additional or different license terms and conditions
      for use, reproduction, or distribution of Your modifications, or
      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.
   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of
      this License, without any additional terms or conditions.
      Notwithstanding the above, nothing herein shall supersede or modify
      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.
   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.
   7. Disclaimer of Warranty. Unless required by applicable law or
      agreed to in writing, Licensor provides the Work (and each
      Contributor provides its Contributions) on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
      implied, including, without limitation, any warranties or conditions
      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
      PARTICULAR PURPOSE. You are solely responsible for determining the
      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.
   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly
      negligent acts) or agreed to in writing, shall any Contributor be
      liable to You for damages, including any direct, indirect, special,
      incidental, or consequential damages of any character arising as a
      result of this License or out of the use or inability to use the
      Work (including but not limited to damages for loss of goodwill,
      work stoppage, computer failure or malfunction, or any and all
      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.
   9. Accepting Warranty or Additional Liability. While redistributing
      the Work or Derivative Works thereof, You may choose to offer,
      and charge a fee for, acceptance of support, warranty, indemnity,
      or other liability obligations and/or rights consistent with this
      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.
   END OF TERMS AND CONDITIONS
   APPENDIX: How to apply the Apache License to your work.
      Copyright 2026 ADD Ideas
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at
          http://www.apache.org/licenses/LICENSE-2.0
      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.
 ==============================================================================
 colorjs.io@0.7.1
 Declared licence: MIT
 Installed from: node_modules/colorjs.io
 ==============================================================================
 --- LICENSE ---
 MIT License
 Copyright (c) 2021 Lea Verou, Chris Lilley
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 ==============================================================================
 react@19.2.8
 Declared licence: MIT
 Installed from: node_modules/react
 ==============================================================================
 --- LICENSE ---
 MIT License
 Copyright (c) Meta Platforms, Inc. and affiliates.
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 ==============================================================================
 react-dom@19.2.8
 Declared licence: MIT
 Installed from: node_modules/react-dom
 ==============================================================================
 --- LICENSE ---
 MIT License
 Copyright (c) Meta Platforms, Inc. and affiliates.
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 ==============================================================================
 scheduler@0.27.0
 Declared licence: MIT
 Installed from: node_modules/scheduler
 ==============================================================================
 --- LICENSE ---
 MIT License
 Copyright (c) Meta Platforms, Inc. and affiliates.
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
@@ -0,0 +1,128 @@
 # Colour Tools
 Colour Tools is a standalone, local-first browser workbench for converting,
 compositing, interpolating, sampling, comparing and organising colours. It is
 part of the
 [add·ideas Toolbox](https://git.add-ideas.de/lotobo/toolbox-portal), but every
 release also runs independently from a static HTTPS host or local preview.
 No colour, image, palette or usage event is sent to a server. Image decoding,
 pixel sampling and palette extraction happen in the browser; the application
 has no analytics, accounts, advertisements or remote lookup feature.
 ## Workspaces
 - **Convert** parses CSS colours and presents copy-ready hex, RGB, HSL, HSV,
  HWB, CMYK, Lab, LCH, OKLab, OKLCH, Display P3, Adobe RGB, ProPhoto RGB,
  Rec. 2020 and XYZ representations. Wide-gamut coordinates remain intact
  until an explicit display or gamut-mapping step. A batch converter isolates
  invalid lines instead of silently dropping them.
 - **Composite** calculates Porter–Duff source-over for an arbitrary ordered
  stack of translucent colours. Each layer has its own alpha, opacity and
  blend mode. The working-light choice makes encoded-sRGB and linear-light
  results explicit, and an optional matte produces an opaque RGB result.
 - **Steps** builds multi-stop colour ramps in perceptual, RGB or cylindrical
  colour spaces. It supports positioned stops, five hue routes, easing,
  premultiplied-alpha interpolation by default with a straight-alpha option,
  and copy-ready CSS and JSON output.
 - **Pick** provides a large keyboard- and pointer-operable HSV picker, alpha
  control, exact CSS entry, browser-native colour input, recent picks and the
  system EyeDropper API where the browser exposes it.
 - **Image** accepts one bounded local PNG, JPEG, WebP, GIF or AVIF. It samples
  an exact coordinate or a configurable average/median neighbourhood and
  extracts two to twelve perceptual palette colours in a worker when
  available.
 - **Contrast** flattens transparency against a stated canvas, reports WCAG 2
  contrast thresholds, finds a nearby passing foreground, compares colours by
  six Delta E methods, checks colour gamuts and previews four approximate
  colour-vision deficiencies.
 - **Palette** creates OKLCH harmonies, tints, shades and tones; keeps a named
  palette in local browser storage; imports common text/JSON token forms; and
  exports CSS, SCSS, JSON, Design Tokens JSON, JavaScript or CSV.
 Adding a generated or sampled colour to the palette is always explicit. The
 saved palette is device-local and can be cleared from the Palette workspace or
 by clearing site storage.
 ## Colour behaviour
 Colour Tools keeps source coordinates outside display gamuts so conversions do
 not destructively clip them. Browser previews and hex exports are mapped to
 sRGB with an explicit indicator when mapping was needed. Compositing is carried
 out in the selected sRGB working light, while interpolation defaults to OKLCH
 for perceptual spacing. See [docs/COLOUR-MATH.md](docs/COLOUR-MATH.md) for the
 formulas, bounds and terminology.
 Contrast pass/fail indicators follow WCAG 2 ratios: 3:1 for non-text UI and
 large text, 4.5:1 for normal AA text and 7:1 for normal AAA text. They are an
 engineering aid, not a complete accessibility audit; typography, state,
 context and non-colour cues still need human review.
 ## Local image handling
 Selecting an image decodes a bounded raster locally with `createImageBitmap`
 where available. The image-element fallback uses a temporary in-memory object
 URL. Decoded resources and any fallback URL are released when the image is
 replaced, removed or the workspace is closed. Palette extraction uses a
 deterministic OKLab clustering implementation and bounded sampling rather than
 uploading the image or retaining a copy. Metadata outside the decoded raster
 is not exposed or stored by the application.
 ## Browser support
 Current evergreen Firefox, Chromium and Safari are the deployment target.
 JavaScript modules, CSS custom properties, Canvas 2D and Web Workers are used.
 The EyeDropper API is progressive enhancement and only appears where a browser
 supports it. Clipboard writes, service workers and EyeDropper access may
 require HTTPS and browser permission; all core calculations work without them.
 The UI supports system, light and dark themes through the shared Toolbox shell.
 Tabs, picker controls and image sampling are keyboard operable, status changes
 use live regions, and swatches are accompanied by machine-readable colour
 values rather than relying on colour alone.
 ## Offline application shell
 Production builds include a relative-scope web app manifest and a
 subpath-aware service worker. After one successful load, the worker caches the
 application shell and same-origin built assets, uses network-first navigation
 with a cached fallback, serves cached static resources where possible and
 removes obsolete cache versions. Service-worker support is optional; colour
 operations never depend on a network connection.
 ## Development
 Requirements: Node.js 22 or newer and npm 11 or newer.
 ```sh
 npm ci
 npm run check
 npm run test:browser
 npm run dev
 ```
 Vite uses `base: './'`, so `dist/` is relocatable to `/` or a nested Toolbox
 path. `toolbox-check` validates standalone and contextual operation.
 The main implementation layers are described in
 [docs/ARCHITECTURE.md](docs/ARCHITECTURE.md). Contributions should follow
 [CONTRIBUTING.md](CONTRIBUTING.md); please report security concerns according
 to [SECURITY.md](SECURITY.md).
 ## Release
 ```sh
 npm run release:artifact
 ```
 This command checks the manifest, types, lint, formatting, unit tests,
 production build, Toolbox contract and browser workflows, then creates a
 deterministic `release/colour-tools-0.1.0.zip` and matching SHA-256 sidecar.
 The archive is a ready-to-host static application and contains project and
 third-party licence notices.
 ## Licence
 Colour Tools is free software under `GPL-3.0-or-later`. See
 [LICENSE](LICENSE). Runtime dependencies retain their respective licences; see
 [THIRD_PARTY_NOTICES.md](THIRD_PARTY_NOTICES.md).
@@ -0,0 +1,50 @@
 # Security policy
 ## Supported versions
 Security fixes are made on the current release line. Users should update to the
 latest published tag and verify the release ZIP against its `.sha256` sidecar.
 ## Reporting a vulnerability
 Please report a suspected vulnerability privately to the repository owner via
 the contact channel shown on the
 [Gitea profile](https://git.add-ideas.de/lotobo) or a private Gitea message. Do
 not include private images, access tokens, unpublished exploit details or other
 sensitive material in a public issue.
 Include the affected version, browser and operating system; a minimal local
 reproduction; the expected impact; and whether the issue requires a crafted
 image, palette or colour string. You should receive acknowledgement within
 seven days. Coordinated disclosure is appreciated while a fix and release are
 prepared.
 ## Security model
 Colour Tools is a static browser application. It has no application backend,
 account system, analytics endpoint or image-upload endpoint. All selected image
 bytes are decoded and processed locally. Saved palette entries use browser
 storage for the current origin. Clipboard, file picker, download and EyeDropper
 actions happen only after a user gesture and remain governed by browser
 permissions.
 File processing is deliberately bounded by encoded byte size, decoded pixel
 count and dimensions. Image palette extraction samples a bounded number of
 pixels and can run in a disposable worker. Object URLs and worker jobs are
 cancelled or released when replaced. Input is displayed as text or parsed by
 typed colour/image APIs; it is not evaluated as script or inserted as trusted
 HTML.
 Production hosts should serve the headers in
 [docs/PRIVACY-SECURITY.md](docs/PRIVACY-SECURITY.md), use HTTPS, keep MIME types
 correct, disable content sniffing and avoid injecting third-party scripts. A
 host can still observe ordinary HTTP metadata for the initial static-file
 request; “local-first” describes application data processing, not anonymity
 from the static host.
 ## Out of scope
 Colour rendering differences between conforming browser/OS colour-management
 pipelines are not vulnerabilities by themselves. Likewise, an approximate
 colour-vision simulation is an educational preview, not a medical diagnosis or
 a complete accessibility guarantee.
@@ -0,0 +1,31 @@
 # Corresponding source and provenance
 The corresponding source for Colour Tools 0.1.0 is:
 https://git.add-ideas.de/lotobo/colour-tools/src/tag/v0.1.0
 Build that tag with Node.js 22 and the exact dependency graph recorded in
 `package-lock.json`:
 ```sh
 npm ci
 npm run release:artifact
 ```
 The generated JavaScript and CSS bundles are not the preferred form for
 modification. No runtime code is loaded from a CDN. The production ZIP contains
 this source pointer, the application licence, the dependency licence inventory,
 and the applicable third-party notices.
 ## Implementation provenance
 - The application is original project code and uses the shared Toolbox SDK
  packages at version 0.2.3 for its manifest contract, shell, and build checks.
 - Colour conversion and adaptation use Color.js 0.7.1. Its MIT licence is
  reproduced in `LICENSES/colorjs.io-MIT.txt`.
 - The compositing, interpolation, palette, image-sampling, contrast, comparison,
  gamut, and colour-vision utilities in `src/colour` and `src/palette` were
  implemented for this project.
 - CSS Color 4 and WCAG 2.2 were used as public technical specifications. No
  source code or branded assets were copied from the example websites that
  informed the feature list.
@@ -0,0 +1,25 @@
 # Third-party notices
 Release preparation collates licence files for the exact locked runtime
 packages into `LICENSES/npm-runtime-licenses.txt` inside the static artifact.
 | Package                          | Version | Licence    | Role                                 | Source                                      |
 | -------------------------------- | ------- | ---------- | ------------------------------------ | ------------------------------------------- |
 | `@add-ideas/toolbox-contract`    | 0.2.3   | Apache-2.0 | manifest and context contract        | https://git.add-ideas.de/lotobo/toolbox-sdk |
 | `@add-ideas/toolbox-shell-react` | 0.2.3   | Apache-2.0 | shared shell, theme and actions      | https://git.add-ideas.de/lotobo/toolbox-sdk |
 | `colorjs.io`                     | 0.7.1   | MIT        | parsing, conversion and colour maths | https://github.com/color-js/color.js        |
 | `react`                          | 19.2.8  | MIT        | application UI                       | https://github.com/facebook/react           |
 | `react-dom`                      | 19.2.8  | MIT        | browser rendering                    | https://github.com/facebook/react           |
 `scheduler` 0.27.0, distributed by the React project under MIT, is the only
 transitive runtime package. Development-only packages build and test the
 source but are not shipped as runtime modules.
 The exact Color.js notice is retained at
 `LICENSES/colorjs.io-MIT.txt`. Apache-2.0 and MIT texts from all installed
 runtime packages are reproduced by the deterministic release-preparation step.
 CSS Color, CSS Compositing and Blending, WCAG and the linked web utilities that
 informed the product requirements are specification or research references
 only. Their source code, artwork and documentation wording are not bundled or
 copied into Colour Tools.
@@ -0,0 +1,19 @@
 # Accessibility notes
 Colour Tools treats colour as data as well as appearance. Swatches are paired
 with textual values, gamut/contrast status uses text and symbols in addition to
 hue, and generated palettes remain usable without visually distinguishing
 every swatch.
 Workspace navigation uses tabs with selected state and arrow/Home/End keyboard
 navigation. Native inputs and labelled controls are preferred. The large picker
 supports arrow-key adjustment and announces its saturation and brightness;
 image sampling supports numeric coordinates and keyboard movement in addition
 to pointer selection. Calculation and file statuses use live regions without
 clearing the last valid result while a user is typing.
 The shared Toolbox shell provides system, light and dark themes. Focus rings,
 touch targets, reflow and text contrast should be checked in all themes and at
 400% zoom. A WCAG contrast result is not itself proof that the complete
 interface conforms: test keyboard order, names/roles/values, error recovery,
 high contrast modes, reduced motion and screen-reader output in context.
@@ -0,0 +1,69 @@
 # Architecture
 Colour Tools is a client-only React application built as relocatable static
 files. The UI and calculation engine are intentionally separated so colour
 operations can be tested without a browser and UI state can keep showing the
 last valid result while an input is incomplete.
 ## Layers
 1. `src/colour/` is the serialisable colour domain. It parses and formats
   colours, converts gamuts, composites layers, interpolates stops, evaluates
   contrast and Delta E, simulates colour-vision deficiencies, and builds or
   exports palettes. Its public API is re-exported from `src/colour/index.ts`.
 2. `src/palette/` contains browser-independent raster bounds, sampling and
   deterministic OKLab clustering. `src/workers/palette.worker.ts` exposes the
   expensive extraction path to a dedicated worker.
 3. `src/components/` contains the seven workspaces and shared accessible
   controls. Workspace selection is represented by a URL fragment, so a view
   can be bookmarked without router or server support.
 4. `src/hooks/` owns bounded device-local UI persistence. Image bytes are not
   stored there.
 5. `src/toolbox/` contains the checked manifest identity. The shared Toolbox
   shell supplies navigation, contextual actions and theme behaviour without
   changing the standalone application domain.
 ## Colour values
 The engine's `ColourValue` is a plain object: colour-space identifier, three
 numeric coordinates and alpha. It deliberately carries coordinates that may
 sit outside a display gamut. Color.js 0.7.1 supplies standards-aligned parsing
 and conversion primitives; Colour Tools wraps these in typed, bounded domain
 operations and stable UI formats.
 Browser preview is a separate operation. It maps a value to sRGB and reports
 whether mapping occurred. This keeps display limitations from mutating the
 source colour used by later conversions or comparisons.
 ## Raster pipeline
 The image picker validates the selected file before decode, rejects excessive
 bytes/dimensions/pixels, then draws the decoded image to a same-origin in-memory
 Canvas 2D surface. Sampling reads a bounded neighbourhood. Palette extraction
 subsamples deterministically, converts points to OKLab and clusters them with a
 fixed initialization and iteration bound. The worker client can fall back to
 the same pure function when workers are unavailable.
 Temporary object URLs are revoked and outstanding extraction is aborted when an
 image is replaced or removed. No image or extracted palette is transmitted.
 ## Build and deployment
 Vite builds with a relative base. `scripts/generate-toolbox-manifest.mjs`
 checks package, application and Toolbox versions plus immutable source
 identity. `scripts/prepare-release-files.mjs` places project documentation and
 the exact installed runtime licence inventory beside the executable app.
 The service worker is relative-scope and deployment-subpath aware. It is
 progressive enhancement: the app remains usable when registration is rejected.
 The deterministic packager rejects symbolic links, source maps, secret-like
 filenames and root-absolute asset references before creating the release ZIP
 and SHA-256 sidecar.
 ## Testing boundaries
 Unit tests cover parsing, numerical operations, invalid inputs, raster bounds,
 sampling and palette determinism. Browser smoke tests run the production build
 under a restrictive policy at `/deep/nested/colour/`, exercise all major
 workspaces and fail on uncaught errors or external network requests. The
 Toolbox contract checker validates the static artifact independently.
@@ -0,0 +1,94 @@
 # Colour mathematics and terminology
 This document records the choices that materially change a result. It is not a
 replacement for CSS Color, Compositing and Blending, or WCAG.
 ## Parsing and conversion
 The parser accepts CSS colour syntax supported by the installed Color.js
 version, including hex and named colours; `rgb()`, `hsl()`, `hwb()`, Lab/LCH
 and OKLab/OKLCH functions; and registered `color()` spaces. Conversion keeps
 finite coordinates outside a target gamut. Hex and ordinary browser sRGB
 previews require mapping; the UI labels when this happened.
 The converter exposes device-oriented and mathematical representations, but a
 numeric tuple is meaningful only with its named colour space, white point,
 transfer curve and alpha convention. CMYK output is a convenient mathematical
 conversion, not a printer ICC separation or proof.
 ## Alpha compositing
 For a source colour over a backdrop, with straight alpha `αs` and `αb`, output
 alpha is:
 ```text
 αo = αs + αb × (1 − αs)
 ```
 For each premultiplied channel under normal source-over:
 ```text
 Co = Cs × αs + Cb × αb × (1 − αs)
 co = Co / αo                         when αo > 0
 ```
 Layers are accumulated from the bottom upward even though the editor displays
 the top layer first. Layer opacity multiplies the colour's own alpha. Blend
 modes are applied before source-over using the model in CSS Compositing and
 Blending.
 “Encoded sRGB” applies the operation directly to sRGB-encoded channel values,
 matching many quick web calculators. “Linear-light sRGB” first removes the
 sRGB transfer curve and is generally the physically meaningful choice for
 mixing emitted light. The two results are expected to differ.
 ## Interpolation
 A ramp samples its first and last stop and distributes missing positions like a
 CSS gradient. Each segment is interpolated in the selected space with the
 chosen easing. Cylindrical spaces need an explicit hue route: shorter, longer,
 increasing, decreasing or raw. The default premultiplies colour components by
 alpha before mixing and unpremultiplies afterwards, preventing hidden channels
 inside a transparent endpoint from tinting the ramp. A straight-alpha toggle
 is available for intentionally reproducing that model. OKLCH is the UI default
 because equal numeric progress tends to look more even than encoded RGB; it
 does not guarantee that every intermediate colour lies in a display gamut.
 ## Gamut mapping
 An in-gamut check does not modify the colour. Display mapping uses an OKLCH
 chroma-reduction method by default; channel clipping is available at the engine
 boundary where explicitly selected. The result includes Delta E OK from the
 source so callers can quantify the change. A browser preview is always mapped
 to sRGB because CSS support and physical displays differ.
 ## Contrast and transparency
 Relative luminance and WCAG 2 contrast are evaluated after translucent
 foreground/background colours are composited over the stated canvas (white by
 default). The ratio is:
 ```text
 (Llighter + 0.05) / (Ldarker + 0.05)
 ```
 The UI reports 3:1, 4.5:1 and 7:1 thresholds and searches for a nearby lighter
 or darker passing foreground. A mathematical pass is only one part of an
 accessibility review; font size/weight, focus states, disabled controls,
 non-colour cues and actual display conditions remain relevant.
 ## Perceptual difference and simulations
 Delta E 76, CMC, CIEDE2000, Delta E OK, ITP and Jz answer different historical
 or application needs; values from different formulas are not interchangeable.
 The colour-vision previews apply bounded matrices in linear sRGB and expose a
 severity control. They are approximations for interface review, not a model of
 every observer and not medical advice.
 ## Palette extraction
 The raster extractor ignores sufficiently transparent pixels, converts bounded
 samples to OKLab and clusters them deterministically. Reported coverage is the
 share of accepted samples assigned to a cluster, not an exact segmentation of
 every source pixel. Small antialiased regions and colour-managed decoding can
 therefore influence the result.
@@ -0,0 +1,60 @@
 # Privacy, security and deployment
 ## Data flow
 Colour input, saved palette entries, selected image bytes, decoded pixels and
 generated exports stay in the browser. The application does not issue API
 requests, load remote fonts, submit analytics or resolve remote colour
 references. A saved palette belongs to the current browser origin and is
 stored until the user clears it or browser storage is removed. Images are
 in-memory only.
 The static host still receives ordinary requests for HTML, JavaScript, CSS,
 icons and worker files on initial load and revalidation. Host logs, reverse
 proxy logs and browser extension behaviour are outside the application's local
 processing boundary.
 ## Recommended headers
 Serve the static artifact over HTTPS and apply a policy equivalent to:
 ```text
 Content-Security-Policy: default-src 'self'; base-uri 'self'; object-src 'none'; frame-ancestors 'none'; form-action 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; connect-src 'self'; worker-src 'self' blob:; manifest-src 'self'
 Cross-Origin-Opener-Policy: same-origin
 Cross-Origin-Resource-Policy: same-origin
 Permissions-Policy: camera=(), microphone=(), geolocation=(), usb=(), payment=()
 Referrer-Policy: no-referrer
 X-Content-Type-Options: nosniff
 ```
 The shared Toolbox shell uses inline style properties for colour previews, so
 `style-src 'unsafe-inline'` is currently required. Do not add
 `script-src 'unsafe-inline'` or third-party script origins. `blob:` is required
 for local image object URLs and may be used for a worker fallback.
 Serve `.js` as `text/javascript`, `.json` as `application/json`, `.webmanifest`
 as `application/manifest+json`, and `.svg` as `image/svg+xml`. Hashed assets may
 use a long immutable cache lifetime; keep `index.html`, `sw.js` and
 `toolbox-app.json` on revalidation/no-cache so releases update predictably.
 ## Reverse-proxy example
 For an nginx deployment rooted at `/apps/colour/`, use `try_files` only to
 resolve actual static files and the directory index; do not rewrite missing
 asset paths to HTML. The application itself uses relative paths and needs no
 server-side router. Keep the `sw.js` scope at the application directory.
 If the app is assembled into toolbox-portal, use the portal's release lock and
 assembly process instead of unpacking files into an existing live directory.
 Verify the ZIP against its SHA-256 sidecar before assembly.
 ## File limits and cleanup
 The image picker enforces encoded-byte, dimension and decoded-pixel limits
 before expensive processing. Sampling radius and palette colour counts are
 bounded. Object URLs, decoded buffers and worker requests are released or
 cancelled when replaced. Browsers and image decoders remain security-sensitive
 dependencies, so deploy current supported browser versions and publish patched
 application releases promptly.
 See [SECURITY.md](../SECURITY.md) for private reporting instructions.
@@ -0,0 +1,19 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64">
  <defs>
    <linearGradient id="paper" x1="8" y1="6" x2="55" y2="61" gradientUnits="userSpaceOnUse">
      <stop stop-color="#fff"/>
      <stop offset="1" stop-color="#ececf4"/>
    </linearGradient>
    <linearGradient id="spectrum" x1="15" y1="44" x2="49" y2="21" gradientUnits="userSpaceOnUse">
      <stop stop-color="#f45274"/>
      <stop offset=".28" stop-color="#f3b93f"/>
      <stop offset=".52" stop-color="#43b978"/>
      <stop offset=".76" stop-color="#3f8ee8"/>
      <stop offset="1" stop-color="#8659d7"/>
    </linearGradient>
  </defs>
  <path d="M12 5h27l13 13v39a3 3 0 0 1-3 3H12a3 3 0 0 1-3-3V8a3 3 0 0 1 3-3Z" fill="url(#paper)" stroke="#403b68" stroke-width="3"/>
  <path d="M39 5v13h13" fill="#deddeb" stroke="#403b68" stroke-width="3" stroke-linejoin="round"/>
  <circle cx="30" cy="37" r="14" fill="url(#spectrum)"/>
  <circle cx="30" cy="37" r="5" fill="#fff" fill-opacity=".92"/>
 </svg>
@@ -0,0 +1,18 @@
 {
  "name": "Colour Tools",
  "short_name": "Colour",
  "description": "Convert, composite, compare and build colours locally.",
  "start_url": "./",
  "scope": "./",
  "display": "standalone",
  "background_color": "#f7f7fb",
  "theme_color": "#2d2859",
  "icons": [
    {
      "src": "./favicon.svg",
      "sizes": "any",
      "type": "image/svg+xml",
      "purpose": "any maskable"
    }
  ]
 }
@@ -0,0 +1,79 @@
 const CACHE_PREFIX = "colour-tools-shell-";
 const CACHE_NAME = `${CACHE_PREFIX}0.1.0`;
 const CORE = ["./", "./manifest.webmanifest", "./favicon.svg"];
 self.addEventListener("install", (event) => {
  event.waitUntil(
    caches.open(CACHE_NAME).then(async (cache) => {
      await cache.addAll(CORE);
      const response = await fetch("./");
      const html = await response.text();
      const assets = [...html.matchAll(/(?:src|href)="(\.\/assets\/[^"]+)"/g)]
        .map((match) => match[1])
        .filter(Boolean);
      await cache.addAll(assets);
    }),
  );
  self.skipWaiting();
 });
 self.addEventListener("activate", (event) => {
  event.waitUntil(
    caches
      .keys()
      .then((keys) =>
        Promise.all(
          keys
            .filter((key) => key.startsWith(CACHE_PREFIX) && key !== CACHE_NAME)
            .map((key) => caches.delete(key)),
        ),
      )
      .then(() => self.clients.claim()),
  );
 });
 self.addEventListener("fetch", (event) => {
  if (event.request.method !== "GET") return;
  const url = new URL(event.request.url);
  if (url.origin !== self.location.origin) return;
  const scope = new URL(self.registration.scope);
  if (!url.pathname.startsWith(scope.pathname)) return;
  if (event.request.mode === "navigate") {
    event.respondWith(
      fetch(event.request)
        .then((response) => {
          if (response.ok) {
            const copy = response.clone();
            void caches
              .open(CACHE_NAME)
              .then((cache) => cache.put(event.request, copy));
          }
          return response;
        })
        .catch(async () => {
          const cached = await caches.match(event.request);
          if (cached) return cached;
          const shellUrl = new URL("./", self.registration.scope).href;
          return (await caches.match(shellUrl)) ?? Response.error();
        }),
    );
    return;
  }
  event.respondWith(
    caches.match(event.request).then(
      (cached) =>
        cached ??
        fetch(event.request).then((response) => {
          if (response.ok) {
            const copy = response.clone();
            void caches
              .open(CACHE_NAME)
              .then((cache) => cache.put(event.request, copy));
          }
          return response;
        }),
    ),
  );
 });
@@ -0,0 +1,51 @@
 {
  "$schema": "https://git.add-ideas.de/lotobo/toolbox-sdk/raw/branch/main/schemas/toolbox-app.v1.schema.json",
  "schemaVersion": 1,
  "id": "de.add-ideas.colour-tools",
  "name": "Colour Tools",
  "version": "0.1.0",
  "description": "Convert, composite, compare and build colours locally in the browser.",
  "entry": "./",
  "icon": "./favicon.svg",
  "categories": ["graphics", "design", "developer"],
  "tags": [
    "colour",
    "color",
    "rgb",
    "rgba",
    "oklch",
    "palette",
    "gradient",
    "contrast",
    "image"
  ],
  "integration": {
    "contextVersion": 1,
    "launchModes": ["navigate", "new-tab"],
    "embedding": "unsupported"
  },
  "requirements": {
    "secureContext": false,
    "workers": true,
    "indexedDb": false,
    "crossOriginIsolated": false,
    "topLevelContext": false
  },
  "privacy": {
    "processing": "local",
    "fileUploads": false,
    "telemetry": false,
    "label": "Colours and images stay in this browser; nothing is uploaded."
  },
  "source": {
    "repository": "https://git.add-ideas.de/lotobo/colour-tools",
    "license": "GPL-3.0-or-later"
  },
  "actions": [
    {
      "id": "source",
      "label": "Source",
      "url": "https://git.add-ideas.de/lotobo/colour-tools"
    }
  ]
 }
@@ -0,0 +1,63 @@
 import { lstat, readFile, writeFile } from "node:fs/promises";
 import { dirname, join, relative } from "node:path";
 import { fileURLToPath } from "node:url";
 import { format } from "prettier";
 const root = join(dirname(fileURLToPath(import.meta.url)), "..");
 const sourcePath = join(root, "src", "toolbox", "manifest.source.json");
 const outputPath = join(root, "public", "toolbox-app.json");
 const source = JSON.parse(await readFile(sourcePath, "utf8"));
 const packageJson = JSON.parse(
  await readFile(join(root, "package.json"), "utf8"),
 );
 const versionSource = await readFile(join(root, "src", "version.ts"), "utf8");
 const applicationVersion =
  /^export const (?:APPLICATION|APP)_VERSION = "([^"]+)";$/mu.exec(
    versionSource,
  )?.[1];
 if (
  source.version !== packageJson.version ||
  applicationVersion !== packageJson.version
 )
  throw new Error(
    `Version drift: manifest ${source.version}, application ${String(applicationVersion)}, package ${packageJson.version}`,
  );
 if (
  source.id !== "de.add-ideas.colour-tools" ||
  source.source?.repository !==
    "https://git.add-ideas.de/lotobo/colour-tools" ||
  source.source?.license !== "GPL-3.0-or-later"
 )
  throw new Error("Manifest source identity is incomplete or inconsistent");
 for (const asset of source.assets ?? []) {
  if (
    typeof asset !== "string" ||
    !asset.startsWith("./") ||
    asset.includes("\\") ||
    asset.split("/").includes("..")
  )
    throw new Error(`Unsafe manifest asset path: ${JSON.stringify(asset)}`);
  const details = await lstat(join(root, "public", asset.slice(2))).catch(
    () => null,
  );
  if (!details?.isFile() || details.isSymbolicLink())
    throw new Error(`Manifest asset is missing or unsafe: ${asset}`);
 }
 const serialized = await format(JSON.stringify(source), {
  filepath: outputPath,
 });
 if (process.argv.includes("--check")) {
  if ((await readFile(outputPath, "utf8").catch(() => "")) !== serialized)
    throw new Error(
      `${relative(root, outputPath)} is stale; run npm run manifest:generate`,
    );
  console.log("Toolbox manifest is synchronized");
 } else {
  await writeFile(outputPath, serialized);
  console.log(`Generated ${relative(root, outputPath)}`);
 }
@@ -0,0 +1,179 @@
 #!/usr/bin/env node
 import { createHash } from "node:crypto";
 import { execFile } from "node:child_process";
 import {
  access,
  chmod,
  copyFile,
  cp,
  lstat,
  mkdir,
  mkdtemp,
  readFile,
  readdir,
  rename,
  rm,
  utimes,
  writeFile,
 } from "node:fs/promises";
 import os from "node:os";
 import path from "node:path";
 import { promisify } from "node:util";
 import { fileURLToPath } from "node:url";
 const execute = promisify(execFile);
 const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
 const packageJson = JSON.parse(
  await readFile(path.join(root, "package.json"), "utf8"),
 );
 const argument = (name, fallback) => {
  const index = process.argv.indexOf(name);
  return index >= 0 ? process.argv[index + 1] : fallback;
 };
 const output = path.resolve(
  root,
  argument("--output", `release/colour-tools-${packageJson.version}.zip`),
 );
 const checksumOutput = `${output}.sha256`;
 const force = process.argv.includes("--force");
 if (
  path.extname(output).toLowerCase() !== ".zip" ||
  output === root ||
  output === path.parse(output).root
 )
  throw new Error("Release output is not a safe ZIP target");
 const exists = (file) =>
  access(file).then(
    () => true,
    () => false,
  );
 if (!force && ((await exists(output)) || (await exists(checksumOutput))))
  throw new Error("Release output already exists; use --force to replace it");
 const input = path.join(root, "dist");
 for (const name of [
  "index.html",
  "manifest.webmanifest",
  "sw.js",
  "toolbox-app.json",
  "favicon.svg",
  "README.md",
  "CHANGELOG.md",
  "CONTRIBUTING.md",
  "LICENSE",
  "SECURITY.md",
  "SOURCE.md",
  "THIRD_PARTY_NOTICES.md",
  "LICENSES/README.md",
  "LICENSES/colorjs.io-MIT.txt",
  "LICENSES/npm-runtime-licenses.txt",
  "docs/ACCESSIBILITY.md",
  "docs/ARCHITECTURE.md",
  "docs/COLOUR-MATH.md",
  "docs/PRIVACY-SECURITY.md",
 ]) {
  const details = await lstat(path.join(input, name)).catch(() => null);
  if (!details?.isFile() || details.isSymbolicLink())
    throw new Error(`Release is missing a regular file: ${name}`);
 }
 const manifest = JSON.parse(
  await readFile(path.join(input, "toolbox-app.json"), "utf8"),
 );
 if (
  manifest.id !== "de.add-ideas.colour-tools" ||
  manifest.version !== packageJson.version ||
  manifest.entry !== "./" ||
  manifest.icon !== "./favicon.svg" ||
  manifest.source?.repository !== "https://git.add-ideas.de/lotobo/colour-tools"
 )
  throw new Error("Packaged Toolbox manifest identity is invalid");
 const html = await readFile(path.join(input, "index.html"), "utf8");
 if (/\b(?:src|href)=["']\//iu.test(html))
  throw new Error("index.html contains a root-absolute asset reference");
 async function collect(directory, prefix = "") {
  const files = [];
  for (const entry of (await readdir(directory, { withFileTypes: true })).sort(
    (left, right) =>
      left.name === right.name ? 0 : left.name < right.name ? -1 : 1,
  )) {
    const absolute = path.join(directory, entry.name);
    const relative = prefix ? `${prefix}/${entry.name}` : entry.name;
    if (entry.isSymbolicLink())
      throw new Error(`Release contains a symbolic link: ${relative}`);
    if (entry.isDirectory()) files.push(...(await collect(absolute, relative)));
    else if (entry.isFile()) files.push({ absolute, relative });
    else throw new Error(`Unsupported release entry: ${relative}`);
  }
  return files;
 }
 const sourceFiles = await collect(input);
 for (const file of sourceFiles)
  if (
    file.relative.endsWith(".map") ||
    /(?:^|\/)(?:\.env(?:\.|$)|id_rsa|id_ed25519|.*\.pem$|.*\.key$)/iu.test(
      file.relative,
    ) ||
    file.relative.startsWith("/") ||
    file.relative.split("/").includes("..")
  )
    throw new Error(`Forbidden release entry: ${file.relative}`);
 await mkdir(path.dirname(output), { recursive: true });
 const stagingRoot = await mkdtemp(path.join(os.tmpdir(), "colour-release-"));
 const publicationRoot = await mkdtemp(
  path.join(path.dirname(output), ".colour-publish-"),
 );
 const stagedTree = path.join(stagingRoot, "tree");
 const stagedArchive = path.join(stagingRoot, path.basename(output));
 try {
  await cp(input, stagedTree, { recursive: true });
  const timestamp = new Date("1980-01-01T00:00:00.000Z");
  for (const file of await collect(stagedTree)) {
    await chmod(file.absolute, 0o644);
    await utimes(file.absolute, timestamp, timestamp);
  }
  await execute(
    "zip",
    [
      "-X",
      "-q",
      "-9",
      stagedArchive,
      ...sourceFiles.map((file) => file.relative),
    ],
    {
      cwd: stagedTree,
      env: { ...process.env, TZ: "UTC" },
      maxBuffer: 1024 * 1024,
    },
  );
  const archive = await readFile(stagedArchive);
  const digest = createHash("sha256").update(archive).digest("hex");
  const stagedChecksum = `${stagedArchive}.sha256`;
  await writeFile(stagedChecksum, `${digest}  ${path.basename(output)}\n`, {
    mode: 0o644,
  });
  const publicationArchive = path.join(publicationRoot, path.basename(output));
  const publicationChecksum = `${publicationArchive}.sha256`;
  await copyFile(stagedArchive, publicationArchive);
  await copyFile(stagedChecksum, publicationChecksum);
  if (force) {
    await rm(output, { force: true });
    await rm(checksumOutput, { force: true });
  }
  await rename(publicationArchive, output);
  await rename(publicationChecksum, checksumOutput);
  console.log(
    `Created ${path.relative(root, output)} (${archive.byteLength} bytes, ${sourceFiles.length} files)\nSHA-256 ${digest}`,
  );
 } finally {
  await rm(stagingRoot, { recursive: true, force: true });
  await rm(publicationRoot, { recursive: true, force: true });
 }
@@ -0,0 +1,72 @@
 import { cp, mkdir, readFile, readdir, rm, writeFile } from "node:fs/promises";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
 const destination = path.join(root, "public");
 const required = [
  "LICENSE",
  "README.md",
  "CHANGELOG.md",
  "CONTRIBUTING.md",
  "SECURITY.md",
  "SOURCE.md",
  "THIRD_PARTY_NOTICES.md",
 ];
 await mkdir(destination, { recursive: true });
 for (const name of required) {
  await readFile(path.join(root, name));
  await cp(path.join(root, name), path.join(destination, name));
 }
 for (const directory of ["LICENSES", "docs"]) {
  const output = path.join(destination, directory);
  await rm(output, { recursive: true, force: true });
  await cp(path.join(root, directory), output, { recursive: true });
 }
 const lock = JSON.parse(
  await readFile(path.join(root, "package-lock.json"), "utf8"),
 );
 const sections = [];
 for (const [location, locked] of Object.entries(lock.packages ?? {}).sort(
  ([left], [right]) => (left === right ? 0 : left < right ? -1 : 1),
 )) {
  if (!location.includes("node_modules/") || locked.dev === true) continue;
  const packageDirectory = path.join(root, location);
  const details = JSON.parse(
    await readFile(path.join(packageDirectory, "package.json"), "utf8"),
  );
  const candidates = (await readdir(packageDirectory))
    .filter((name) => /^(?:licen[cs]e|copying|notice)(?:\.|$)/iu.test(name))
    .sort();
  const texts = [];
  for (const candidate of candidates) {
    try {
      texts.push(
        `--- ${candidate} ---\n${await readFile(path.join(packageDirectory, candidate), "utf8")}`,
      );
    } catch {
      /* Ignore directories and non-text aliases. */
    }
  }
  sections.push(
    [
      "=".repeat(78),
      `${details.name}@${details.version}`,
      `Declared licence: ${details.license ?? locked.license ?? "See upstream"}`,
      `Installed from: ${location}`,
      "=".repeat(78),
      texts.join("\n\n") ||
        "No package-local licence file was present; see THIRD_PARTY_NOTICES.md.",
    ].join("\n"),
  );
 }
 await writeFile(
  path.join(destination, "LICENSES", "npm-runtime-licenses.txt"),
  `${sections.join("\n\n").trimEnd()}\n`,
 );
 console.log("Prepared static release documentation and notices");
@@ -0,0 +1,80 @@
 import { createServer } from "node:http";
 import { readFile, stat } from "node:fs/promises";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 const root = path.resolve(
  path.dirname(fileURLToPath(import.meta.url)),
  "..",
  "dist",
 );
 const nestedPrefix = "/deep/nested/colour/";
 const mediaTypes = new Map([
  [".css", "text/css; charset=utf-8"],
  [".html", "text/html; charset=utf-8"],
  [".js", "text/javascript; charset=utf-8"],
  [".json", "application/json; charset=utf-8"],
  [".webmanifest", "application/manifest+json; charset=utf-8"],
  [".svg", "image/svg+xml"],
  [".md", "text/markdown; charset=utf-8"],
  [".txt", "text/plain; charset=utf-8"],
  [".wasm", "application/wasm"],
  [".png", "image/png"],
  [".jpg", "image/jpeg"],
  [".jpeg", "image/jpeg"],
  [".webp", "image/webp"],
  [".avif", "image/avif"],
 ]);
 const headers = {
  "Content-Security-Policy":
    "default-src 'self'; base-uri 'self'; object-src 'none'; frame-ancestors 'none'; form-action 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; connect-src 'self'; worker-src 'self' blob:; manifest-src 'self'",
  "Cross-Origin-Opener-Policy": "same-origin",
  "Cross-Origin-Resource-Policy": "same-origin",
  "Permissions-Policy":
    "camera=(), microphone=(), geolocation=(), usb=(), payment=()",
  "Referrer-Policy": "no-referrer",
  "X-Content-Type-Options": "nosniff",
 };
 function safeFile(requestPath) {
  const decoded = decodeURIComponent(requestPath);
  const relative = decoded.startsWith(nestedPrefix)
    ? decoded.slice(nestedPrefix.length)
    : decoded.replace(/^\/+/, "");
  const normalized = path.posix.normalize(relative || "index.html");
  if (
    normalized === ".." ||
    normalized.startsWith("../") ||
    path.isAbsolute(normalized)
  )
    return null;
  return path.join(root, normalized);
 }
 const server = createServer(async (request, response) => {
  try {
    const url = new URL(request.url ?? "/", "http://127.0.0.1");
    let file = safeFile(url.pathname);
    if (!file) {
      response.writeHead(400).end("Bad request");
      return;
    }
    if ((await stat(file).catch(() => null))?.isDirectory())
      file = path.join(file, "index.html");
    const content = await readFile(file);
    response.writeHead(200, {
      "Content-Type":
        mediaTypes.get(path.extname(file)) ?? "application/octet-stream",
      "Cache-Control": "no-cache",
      ...headers,
    });
    response.end(content);
  } catch {
    response.writeHead(404, { "Content-Type": "text/plain; charset=utf-8" });
    response.end("Not found");
  }
 });
 server.listen(4173, "127.0.0.1", () =>
  console.log("Colour Tools test server listening on http://127.0.0.1:4173"),
 );
@@ -0,0 +1,42 @@
 import { lazy, Suspense, useState } from "react";
 import { AppShell } from "@add-ideas/toolbox-shell-react";
 import "@add-ideas/toolbox-shell-react/styles.css";
 import "./styles.css";
 import { AppErrorBoundary } from "./components/AppErrorBoundary";
 import { HelpDialog } from "./components/HelpDialog";
 import { manifest } from "./toolbox/manifest";
 const Workbench = lazy(async () => ({
  default: (await import("./components/Workbench")).Workbench,
 }));
 export function App() {
  const [helpOpen, setHelpOpen] = useState(false);
  return (
    <AppErrorBoundary>
      <AppShell
        app={manifest}
        manifestUrl="./toolbox-app.json"
        helpAction={{ onClick: () => setHelpOpen(true) }}
        onContextError={(error) =>
          console.warn(
            "Toolbox context unavailable; continuing standalone.",
            error,
          )
        }
      >
        <Suspense
          fallback={
            <p className="workbench-loading" role="status">
              Preparing the local colour workbench…
            </p>
          }
        >
          <Workbench />
        </Suspense>
      </AppShell>
      <HelpDialog open={helpOpen} onClose={() => setHelpOpen(false)} />
    </AppErrorBoundary>
  );
 }
@@ -0,0 +1,209 @@
 import {
  asColor,
  clamp,
  colorFrom,
  lineariseSrgb,
  srgbChannels,
  toColourValue,
 } from "./internal";
 import { compositeSourceOver } from "./composite";
 import { formatColour, toSrgbCss } from "./format";
 import { mapToGamut } from "./gamut";
 import { parseColour } from "./parse";
 import type {
  ColourInput,
  ColourValue,
  ContrastOptions,
  ContrastReport,
  ContrastSuggestion,
 } from "./types";
 const WHITE: ColourValue = { space: "srgb", coords: [1, 1, 1], alpha: 1 };
 export function flattenColour(
  foreground: ColourInput,
  background: ColourInput,
 ): ColourValue {
  // Browser alpha compositing for ordinary CSS sRGB colours is performed in the
  // encoded colour space; contrast must inspect the pixels users actually see.
  return compositeSourceOver(foreground, background, { space: "srgb" }).colour;
 }
 function opaqueCanvas(input: ColourInput | undefined): ColourValue {
  const canvas = parseColour(input ?? WHITE);
  return canvas.alpha >= 1 ? canvas : flattenColour(canvas, WHITE);
 }
 function flattenedPair(
  foreground: ColourInput,
  background: ColourInput,
  options: ContrastOptions,
 ): { foreground: ColourValue; background: ColourValue } {
  const canvas = opaqueCanvas(options.canvas);
  const flattenedBackground = flattenColour(background, canvas);
  const flattenedForeground = flattenColour(foreground, flattenedBackground);
  return { foreground: flattenedForeground, background: flattenedBackground };
 }
 export function relativeLuminance(input: ColourInput): number {
  const [red, green, blue] = srgbChannels(parseColour(input));
  return (
    0.2126 * lineariseSrgb(red) +
    0.7152 * lineariseSrgb(green) +
    0.0722 * lineariseSrgb(blue)
  );
 }
 export function contrastRatio(
  foreground: ColourInput,
  background: ColourInput,
  options: ContrastOptions = {},
 ): number {
  const pair = flattenedPair(foreground, background, options);
  const first = relativeLuminance(pair.foreground);
  const second = relativeLuminance(pair.background);
  const lighter = Math.max(first, second);
  const darker = Math.min(first, second);
  return (lighter + 0.05) / (darker + 0.05);
 }
 export function contrastReport(
  foreground: ColourInput,
  background: ColourInput,
  options: ContrastOptions = {},
 ): ContrastReport {
  const foregroundValue = parseColour(foreground);
  const backgroundValue = parseColour(background);
  const pair = flattenedPair(foregroundValue, backgroundValue, options);
  const ratio = contrastRatio(foregroundValue, backgroundValue, options);
  return {
    ratio,
    foreground: foregroundValue,
    background: backgroundValue,
    flattenedForeground: pair.foreground,
    flattenedBackground: pair.background,
    passes: {
      aaLarge: ratio >= 3,
      aaaLarge: ratio >= 4.5,
      aaNormal: ratio >= 4.5,
      aaaNormal: ratio >= 7,
      nonText: ratio >= 3,
    },
  };
 }
 interface Candidate {
  colour: ColourValue;
  ratio: number;
  difference: number;
  lightness: number;
 }
 function candidateAtLightness(
  original: ColourValue,
  oklch: readonly number[],
  lightness: number,
  background: ColourInput,
  target: number,
  options: ContrastOptions,
 ): Candidate | undefined {
  const candidate = mapToGamut(
    toColourValue(
      colorFrom(
        "oklch",
        [lightness, oklch[1] ?? 0, oklch[2] ?? 0],
        original.alpha,
      ),
    ),
  );
  candidate.alpha = original.alpha;
  const ratio = contrastRatio(candidate, background, options);
  if (ratio + 1e-9 < target) return undefined;
  return {
    colour: candidate,
    ratio,
    difference: asColor(original).deltaEOK(asColor(candidate)),
    lightness,
  };
 }
 export function nearestPassingColour(
  foreground: ColourInput,
  background: ColourInput,
  target = 4.5,
  options: ContrastOptions = {},
 ): ContrastSuggestion | null {
  if (!Number.isFinite(target) || target < 1 || target > 21) {
    throw new RangeError("Contrast target must be between 1 and 21.");
  }
  const original = parseColour(foreground);
  const originalRatio = contrastRatio(original, background, options);
  const originalOklch = asColor(original)
    .to("oklch")
    .coords.map((coordinate) => Number(coordinate ?? 0));
  const originalLightness = clamp(originalOklch[0] ?? 0);
  if (originalRatio >= target) {
    return {
      colour: original,
      css: toSrgbCss(original),
      hex: formatColour(original, original.alpha < 1 ? "hex8" : "hex"),
      ratio: originalRatio,
      deltaEOK: 0,
      direction: originalLightness >= 0.5 ? "lighter" : "darker",
    };
  }
  let best: Candidate | undefined;
  const consider = (candidate: Candidate | undefined): void => {
    if (!candidate) return;
    if (
      !best ||
      candidate.difference < best.difference - 1e-9 ||
      (Math.abs(candidate.difference - best.difference) <= 1e-9 &&
        candidate.ratio < best.ratio)
    ) {
      best = candidate;
    }
  };
  for (let index = 0; index <= 400; index += 1) {
    consider(
      candidateAtLightness(
        original,
        originalOklch,
        index / 400,
        background,
        target,
        options,
      ),
    );
  }
  if (!best) return null;
  const coarse = best as Candidate;
  const lower = clamp(coarse.lightness - 1 / 400);
  const upper = clamp(coarse.lightness + 1 / 400);
  for (let index = 0; index <= 100; index += 1) {
    const lightness = lower + ((upper - lower) * index) / 100;
    consider(
      candidateAtLightness(
        original,
        originalOklch,
        lightness,
        background,
        target,
        options,
      ),
    );
  }
  const chosen = best as Candidate;
  return {
    colour: chosen.colour,
    css: toSrgbCss(chosen.colour),
    hex: formatColour(chosen.colour, chosen.colour.alpha < 1 ? "hex8" : "hex"),
    ratio: chosen.ratio,
    deltaEOK: chosen.difference,
    direction: chosen.lightness >= originalLightness ? "lighter" : "darker",
  };
 }
@@ -0,0 +1,4 @@
 declare module "colorjs.io/dist/color.js" {
  export { default } from "colorjs.io";
  export type * from "colorjs.io";
 }
@@ -0,0 +1,115 @@
 import {
  asColor,
  clamp,
  encodeSrgb,
  lineariseSrgb,
  srgbChannels,
 } from "./internal";
 import { mapToGamut } from "./gamut";
 import { parseColour } from "./parse";
 import type {
  ColourCoordinates,
  ColourInput,
  ColourValue,
  ColourVisionDeficiency,
  ColourVisionOptions,
  DeltaEMethod,
 } from "./types";
 export function deltaE(
  first: ColourInput,
  second: ColourInput,
  method: DeltaEMethod = "2000",
 ): number {
  const left = asColor(parseColour(first));
  const right = asColor(parseColour(second));
  switch (method) {
    case "76":
      return left.deltaE76(right);
    case "cmc":
      return left.deltaECMC(right);
    case "2000":
      return left.deltaE2000(right);
    case "ok":
      return left.deltaEOK(right);
    case "itp":
      return left.deltaEITP(right);
    case "jz":
      return left.deltaEJz(right);
  }
 }
 type Matrix = readonly [
  readonly [number, number, number],
  readonly [number, number, number],
  readonly [number, number, number],
 ];
 // Full-severity Machado et al. matrices, applied to linear-light sRGB.
 const VISION_MATRICES: Record<ColourVisionDeficiency, Matrix> = {
  protanopia: [
    [0.152286, 1.052583, -0.204868],
    [0.114503, 0.786281, 0.099216],
    [-0.003882, -0.048116, 1.051998],
  ],
  deuteranopia: [
    [0.367322, 0.860646, -0.227968],
    [0.280085, 0.672501, 0.047413],
    [-0.01182, 0.04294, 0.968881],
  ],
  tritanopia: [
    [1.255528, -0.076749, -0.178779],
    [-0.078411, 0.930809, 0.147602],
    [0.004733, 0.691367, 0.3039],
  ],
  achromatopsia: [
    [0.2126, 0.7152, 0.0722],
    [0.2126, 0.7152, 0.0722],
    [0.2126, 0.7152, 0.0722],
  ],
 };
 function multiply(
  matrix: Matrix,
  vector: ColourCoordinates,
 ): ColourCoordinates {
  return matrix.map(
    (row) => row[0] * vector[0] + row[1] * vector[1] + row[2] * vector[2],
  ) as ColourCoordinates;
 }
 export function simulateColourVision(
  input: ColourInput,
  deficiency: ColourVisionDeficiency,
  options: ColourVisionOptions = {},
 ): ColourValue {
  const source = parseColour(input);
  const severity = clamp(options.severity ?? 1);
  const encoded = srgbChannels(source);
  const linear = encoded.map(lineariseSrgb) as ColourCoordinates;
  const simulated = multiply(VISION_MATRICES[deficiency], linear);
  const mixed = linear.map(
    (channel, index) =>
      channel + ((simulated[index] ?? channel) - channel) * severity,
  );
  const result: ColourValue = {
    space: "srgb",
    coords: mixed.map(encodeSrgb) as ColourCoordinates,
    alpha: source.alpha,
  };
  return options.mapToSrgb === false
    ? result
    : mapToGamut(result, { method: "clip" });
 }
 export function simulateColourVisionSet(
  input: ColourInput,
  options: ColourVisionOptions = {},
 ): Record<ColourVisionDeficiency, ColourValue> {
  return {
    protanopia: simulateColourVision(input, "protanopia", options),
    deuteranopia: simulateColourVision(input, "deuteranopia", options),
    tritanopia: simulateColourVision(input, "tritanopia", options),
    achromatopsia: simulateColourVision(input, "achromatopsia", options),
  };
 }
@@ -0,0 +1,244 @@
 import { clamp, encodeSrgb, lineariseSrgb, srgbChannels } from "./internal";
 import { formatColour, toSrgbCss } from "./format";
 import { parseColour } from "./parse";
 import type {
  BlendMode,
  ColourCoordinates,
  ColourInput,
  ColourValue,
  CompositeLayer,
  CompositeOptions,
  CompositeResult,
  CompositingSpace,
  SourceOverOptions,
 } from "./types";
 function luminosity([red, green, blue]: ColourCoordinates): number {
  return 0.3 * red + 0.59 * green + 0.11 * blue;
 }
 function saturation(channels: ColourCoordinates): number {
  return Math.max(...channels) - Math.min(...channels);
 }
 function clipColour(channels: ColourCoordinates): ColourCoordinates {
  const lightness = luminosity(channels);
  const minimum = Math.min(...channels);
  const maximum = Math.max(...channels);
  let output = [...channels] as ColourCoordinates;
  if (minimum < 0) {
    output = output.map(
      (channel) =>
        lightness + ((channel - lightness) * lightness) / (lightness - minimum),
    ) as ColourCoordinates;
  }
  if (maximum > 1) {
    output = output.map(
      (channel) =>
        lightness +
        ((channel - lightness) * (1 - lightness)) / (maximum - lightness),
    ) as ColourCoordinates;
  }
  return output;
 }
 function setLuminosity(
  channels: ColourCoordinates,
  target: number,
 ): ColourCoordinates {
  const difference = target - luminosity(channels);
  return clipColour(
    channels.map((channel) => channel + difference) as ColourCoordinates,
  );
 }
 function setSaturation(
  channels: ColourCoordinates,
  target: number,
 ): ColourCoordinates {
  const indices = [0, 1, 2] as const;
  const sorted = [...indices].sort(
    (first, second) => channels[first] - channels[second],
  );
  const minimumIndex = sorted[0] ?? 0;
  const middleIndex = sorted[1] ?? 1;
  const maximumIndex = sorted[2] ?? 2;
  const minimum = channels[minimumIndex];
  const maximum = channels[maximumIndex];
  const output: ColourCoordinates = [0, 0, 0];
  if (maximum > minimum) {
    output[middleIndex] =
      ((channels[middleIndex] - minimum) * target) / (maximum - minimum);
    output[maximumIndex] = target;
  }
  output[minimumIndex] = 0;
  return output;
 }
 function softLight(backdrop: number, source: number): number {
  if (source <= 0.5)
    return backdrop - (1 - 2 * source) * backdrop * (1 - backdrop);
  const d =
    backdrop <= 0.25
      ? ((16 * backdrop - 12) * backdrop + 4) * backdrop
      : Math.sqrt(backdrop);
  return backdrop + (2 * source - 1) * (d - backdrop);
 }
 function blendChannel(
  backdrop: number,
  source: number,
  mode: BlendMode,
 ): number {
  switch (mode) {
    case "multiply":
      return backdrop * source;
    case "screen":
      return backdrop + source - backdrop * source;
    case "overlay":
      return backdrop <= 0.5
        ? 2 * backdrop * source
        : 1 - 2 * (1 - backdrop) * (1 - source);
    case "darken":
      return Math.min(backdrop, source);
    case "lighten":
      return Math.max(backdrop, source);
    case "color-dodge":
      return source >= 1 ? 1 : Math.min(1, backdrop / (1 - source));
    case "color-burn":
      return source <= 0 ? 0 : 1 - Math.min(1, (1 - backdrop) / source);
    case "hard-light":
      return source <= 0.5
        ? 2 * backdrop * source
        : 1 - 2 * (1 - backdrop) * (1 - source);
    case "soft-light":
      return softLight(backdrop, source);
    case "difference":
      return Math.abs(backdrop - source);
    case "exclusion":
      return backdrop + source - 2 * backdrop * source;
    case "normal":
    case "hue":
    case "saturation":
    case "color":
    case "luminosity":
      return source;
  }
 }
 function blend(
  backdrop: ColourCoordinates,
  source: ColourCoordinates,
  mode: BlendMode,
 ): ColourCoordinates {
  if (["hue", "saturation", "color", "luminosity"].includes(mode)) {
    const nonSeparable =
      mode === "hue"
        ? setLuminosity(
            setSaturation(source, saturation(backdrop)),
            luminosity(backdrop),
          )
        : mode === "saturation"
          ? setLuminosity(
              setSaturation(backdrop, saturation(source)),
              luminosity(backdrop),
            )
          : mode === "color"
            ? setLuminosity(source, luminosity(backdrop))
            : setLuminosity(backdrop, luminosity(source));
    return nonSeparable.map((channel) => clamp(channel)) as ColourCoordinates;
  }
  return backdrop.map((channel, index) =>
    clamp(blendChannel(channel, source[index] ?? 0, mode)),
  ) as ColourCoordinates;
 }
 function channelsFor(
  input: ColourInput,
  space: CompositingSpace,
 ): ColourCoordinates {
  const channels = srgbChannels(parseColour(input));
  return space === "linear-srgb"
    ? (channels.map(lineariseSrgb) as ColourCoordinates)
    : channels;
 }
 function compositeValues(
  source: ColourValue,
  backdrop: ColourValue,
  space: CompositingSpace,
  mode: BlendMode,
  opacity: number,
 ): ColourValue {
  const sourceChannels = channelsFor(source, space);
  const backdropChannels = channelsFor(backdrop, space);
  const sourceAlpha = clamp(source.alpha * clamp(opacity));
  const backdropAlpha = clamp(backdrop.alpha);
  const outputAlpha = sourceAlpha + backdropAlpha * (1 - sourceAlpha);
  if (outputAlpha <= 0) return { space: "srgb", coords: [0, 0, 0], alpha: 0 };
  const blended = blend(backdropChannels, sourceChannels, mode);
  const output = sourceChannels.map((sourceChannel, index) => {
    const backdropChannel = backdropChannels[index] ?? 0;
    const blendChannelValue = blended[index] ?? sourceChannel;
    const premultiplied =
      sourceAlpha * (1 - backdropAlpha) * sourceChannel +
      sourceAlpha * backdropAlpha * blendChannelValue +
      (1 - sourceAlpha) * backdropAlpha * backdropChannel;
    return premultiplied / outputAlpha;
  }) as ColourCoordinates;
  const encoded =
    space === "linear-srgb"
      ? (output.map(encodeSrgb) as ColourCoordinates)
      : output;
  return {
    space: "srgb",
    coords: encoded.map((channel) => clamp(channel)) as ColourCoordinates,
    alpha: outputAlpha,
  };
 }
 function result(colour: ColourValue): CompositeResult {
  return {
    colour,
    css: toSrgbCss(colour),
    hex: formatColour(colour, colour.alpha < 1 ? "hex8" : "hex"),
  };
 }
 export function compositeSourceOver(
  foreground: ColourInput,
  background: ColourInput,
  options: SourceOverOptions = {},
 ): CompositeResult {
  return result(
    compositeValues(
      parseColour(foreground),
      parseColour(background),
      options.space ?? "srgb",
      options.blendMode ?? "normal",
      options.opacity ?? 1,
    ),
  );
 }
 export function compositeLayers(
  layers: readonly CompositeLayer[],
  options: CompositeOptions = {},
 ): CompositeResult {
  if (layers.length === 0)
    return result({ space: "srgb", coords: [0, 0, 0], alpha: 0 });
  const ordered =
    options.order === "top-to-bottom" ? [...layers].reverse() : [...layers];
  let accumulator: ColourValue = { space: "srgb", coords: [0, 0, 0], alpha: 0 };
  for (const layer of ordered) {
    accumulator = compositeValues(
      parseColour(layer.colour),
      accumulator,
      options.space ?? "srgb",
      layer.blendMode ?? "normal",
      layer.opacity ?? 1,
    );
  }
  return result(accumulator);
 }
@@ -0,0 +1,268 @@
 import {
  alphaText,
  asColor,
  clamp,
  mappedColor,
  numberText,
  round,
  srgbChannels,
  toColourValue,
 } from "./internal";
 import { parseColour } from "./parse";
 import type {
  ColourFormat,
  ColourInput,
  ConversionRow,
  FormatColourOptions,
  SrgbPreview,
 } from "./types";
 const FORMAT_LABELS: Record<ColourFormat, string> = {
  hex: "HEX",
  hex8: "HEX + alpha",
  rgb: "RGB",
  rgba: "RGBA",
  hsl: "HSL",
  hsv: "HSV / HSB",
  hwb: "HWB",
  cmyk: "CMYK",
  lab: "CIELAB",
  lch: "CIELCH",
  oklab: "OKLab",
  oklch: "OKLCH",
  p3: "Display P3",
  rec2020: "Rec. 2020",
  a98rgb: "Adobe RGB (1998)",
  prophoto: "ProPhoto RGB",
  "xyz-d50": "XYZ D50",
  "xyz-d65": "XYZ D65",
  css: "Original CSS",
 };
 export const DEFAULT_CONVERSION_FORMATS: readonly ColourFormat[] = [
  "hex",
  "hex8",
  "rgb",
  "hsl",
  "hsv",
  "hwb",
  "cmyk",
  "lab",
  "lch",
  "oklab",
  "oklch",
  "p3",
  "rec2020",
 ] as const;
 function byte(value: number): number {
  return Math.round(clamp(value) * 255);
 }
 function byteHex(value: number): string {
  return byte(value).toString(16).padStart(2, "0");
 }
 function asHex(input: ColourInput, includeAlpha: boolean): string {
  const value = parseColour(input);
  const channels = srgbChannels(value);
  const rgb = channels.map(byteHex).join("");
  return `#${rgb}${includeAlpha ? byteHex(value.alpha) : ""}`;
 }
 function percent(value: number, precision: number): string {
  return `${numberText(value, precision)}%`;
 }
 function functional(
  name: string,
  coords: readonly string[],
  alpha: number,
  includeAlpha: boolean,
 ): string {
  return `${name}(${coords.join(" ")}${includeAlpha && alpha < 1 ? ` / ${alphaText(alpha)}` : ""})`;
 }
 function serialiseColorFunction(
  space: string,
  coords: readonly number[],
  alpha: number,
  precision: number,
 ): string {
  return `color(${space} ${coords.map((coordinate) => numberText(coordinate, precision)).join(" ")}${
    alpha < 1 ? ` / ${alphaText(alpha)}` : ""
  })`;
 }
 export function formatColour(
  input: ColourInput,
  format: ColourFormat = "css",
  options: FormatColourOptions = {},
 ): string {
  const precision = options.precision ?? 4;
  const value = parseColour(input);
  const alpha = value.alpha;
  const includeAlpha = options.includeAlpha ?? alpha < 1;
  if (format === "hex") return asHex(value, false);
  if (format === "hex8") return asHex(value, true);
  if (format === "rgb" || format === "rgba") {
    const channels = srgbChannels(value, options.mapToSrgb ?? true).map(byte);
    const forceAlpha = format === "rgba" || includeAlpha;
    return forceAlpha
      ? `rgba(${channels.join(", ")}, ${alphaText(alpha)})`
      : `rgb(${channels.join(", ")})`;
  }
  if (format === "cmyk") {
    const [red, green, blue] = srgbChannels(value, options.mapToSrgb ?? true);
    const black = 1 - Math.max(red, green, blue);
    const denominator = 1 - black;
    const cyan = denominator <= 1e-12 ? 0 : (1 - red - black) / denominator;
    const magenta =
      denominator <= 1e-12 ? 0 : (1 - green - black) / denominator;
    const yellow = denominator <= 1e-12 ? 0 : (1 - blue - black) / denominator;
    return functional(
      "cmyk",
      [cyan, magenta, yellow, black].map((channel) =>
        percent(channel * 100, precision),
      ),
      alpha,
      includeAlpha,
    );
  }
  const color = asColor(value);
  if (format === "hsl" || format === "hsv" || format === "hwb") {
    const converted = color.to(format);
    const [hue, first, second] = converted.coords.map((coordinate) =>
      Number(coordinate ?? 0),
    );
    return functional(
      format,
      [
        numberText(hue ?? 0, precision),
        percent(first ?? 0, precision),
        percent(second ?? 0, precision),
      ],
      alpha,
      includeAlpha,
    );
  }
  const space =
    format === "p3"
      ? "p3"
      : format === "a98rgb"
        ? "a98rgb"
        : format === "prophoto"
          ? "prophoto"
          : format;
  if (format === "lab" || format === "lch") {
    const converted = color.to(space);
    const coords = converted.coords.map((coordinate) =>
      Number(coordinate ?? 0),
    );
    return functional(
      format,
      [
        percent(coords[0] ?? 0, precision),
        numberText(coords[1] ?? 0, precision),
        numberText(coords[2] ?? 0, precision),
      ],
      alpha,
      includeAlpha,
    );
  }
  if (format === "oklab" || format === "oklch") {
    const converted = color.to(space);
    const coords = converted.coords.map((coordinate) =>
      Number(coordinate ?? 0),
    );
    return functional(
      format,
      [
        percent((coords[0] ?? 0) * 100, precision),
        numberText(coords[1] ?? 0, precision),
        numberText(coords[2] ?? 0, precision),
      ],
      alpha,
      includeAlpha,
    );
  }
  if (
    ["p3", "rec2020", "a98rgb", "prophoto", "xyz-d50", "xyz-d65"].includes(
      format,
    )
  ) {
    const converted = color.to(space);
    const cssSpace =
      format === "p3"
        ? "display-p3"
        : format === "a98rgb"
          ? "a98-rgb"
          : format === "prophoto"
            ? "prophoto-rgb"
            : format;
    return serialiseColorFunction(
      cssSpace,
      converted.coords.map((coordinate) =>
        round(Number(coordinate ?? 0), precision),
      ),
      alpha,
      precision,
    );
  }
  if (format === "css") {
    return color.toString({ precision, inGamut: options.mapToSrgb === true });
  }
  // Exhaustiveness safeguard for callers compiled against older declarations.
  return color.toString({ precision, inGamut: false });
 }
 export function conversionRows(
  input: ColourInput,
  formats: readonly ColourFormat[] = DEFAULT_CONVERSION_FORMATS,
 ): ConversionRow[] {
  return formats.map((format) => {
    const value = formatColour(input, format);
    return {
      id: format,
      label: FORMAT_LABELS[format],
      value,
      copyValue: value,
    };
  });
 }
 export const formatRows = conversionRows;
 export function toSrgbPreview(input: ColourInput): SrgbPreview {
  const value = parseColour(input);
  const original = asColor(value);
  const mapped = mappedColor(value, "srgb");
  const rgb = mapped.coords.map((coordinate) =>
    clamp(Number(coordinate ?? 0)),
  ) as [number, number, number];
  const integerChannels = rgb.map(byte);
  return {
    css:
      value.alpha < 1
        ? `rgb(${integerChannels.join(" ")} / ${alphaText(value.alpha)})`
        : `rgb(${integerChannels.join(" ")})`,
    hex: formatColour(toColourValue(mapped), value.alpha < 1 ? "hex8" : "hex", {
      includeAlpha: value.alpha < 1,
    }),
    rgb,
    alpha: value.alpha,
    wasMapped: !original.inGamut("srgb"),
  };
 }
 export function toSrgbCss(input: ColourInput): string {
  return toSrgbPreview(input).css;
 }
@@ -0,0 +1,65 @@
 import { asColor, toColourValue } from "./internal";
 import { parseColour } from "./parse";
 import { formatColour, toSrgbCss } from "./format";
 import type {
  ColourInput,
  ColourValue,
  GamutMappingOptions,
  GamutReport,
  GamutSpaceReport,
 } from "./types";
 const GAMUT_LABELS: Readonly<Record<string, string>> = {
  srgb: "sRGB",
  p3: "Display P3",
  rec2020: "Rec. 2020",
  a98rgb: "Adobe RGB (1998)",
  prophoto: "ProPhoto RGB",
 };
 export const DEFAULT_GAMUT_SPACES = ["srgb", "p3", "rec2020"] as const;
 export function mapToGamut(
  input: ColourInput,
  options: GamutMappingOptions = {},
 ): ColourValue {
  const target = options.target ?? "srgb";
  const method = options.method === "clip" ? "clip" : "oklch.c";
  const converted = asColor(parseColour(input)).to(target);
  const mapped = converted.inGamut(target)
    ? converted
    : converted.toGamut({ space: target, method });
  return toColourValue(mapped.to(target));
 }
 function reportSpace(input: ColourValue, space: string): GamutSpaceReport {
  const source = asColor(input);
  const inGamut = source.inGamut(space);
  const mapped = mapToGamut(input, { target: space });
  const format =
    space === "p3"
      ? "p3"
      : space === "rec2020"
        ? "rec2020"
        : space === "a98rgb"
          ? "a98rgb"
          : space === "prophoto"
            ? "prophoto"
            : undefined;
  return {
    space,
    label: GAMUT_LABELS[space] ?? space,
    inGamut,
    mapped,
    mappedCss: format ? formatColour(mapped, format) : toSrgbCss(mapped),
    deltaEOK: inGamut ? 0 : source.deltaEOK(asColor(mapped)),
  };
 }
 export function gamutReport(
  input: ColourInput,
  spaces: readonly string[] = DEFAULT_GAMUT_SPACES,
 ): GamutReport {
  const source = parseColour(input);
  return { source, spaces: spaces.map((space) => reportSpace(source, space)) };
 }
@@ -0,0 +1,48 @@
 export {
  ColourParseError,
  parseColour,
  parseColourList,
  tryParseColour,
 } from "./parse";
 export {
  DEFAULT_CONVERSION_FORMATS,
  conversionRows,
  formatColour,
  formatRows,
  toSrgbCss,
  toSrgbPreview,
 } from "./format";
 export { DEFAULT_GAMUT_SPACES, gamutReport, mapToGamut } from "./gamut";
 export { compositeLayers, compositeSourceOver } from "./composite";
 export { interpolateColourStops, interpolateStops } from "./interpolate";
 export {
  contrastRatio,
  contrastReport,
  flattenColour,
  nearestPassingColour,
  relativeLuminance,
 } from "./accessibility";
 export {
  deltaE,
  simulateColourVision,
  simulateColourVisionSet,
 } from "./compare";
 export {
  colourHarmony,
  exportCssVariables,
  exportCsvPalette,
  exportDesignTokens,
  exportJsonPalette,
  exportPalette,
  exportScssVariables,
  exportTailwindPalette,
  generateHarmony,
  normaliseTokenName,
  parseNamedColourList,
  parsePaletteList,
  shades,
  tints,
  tones,
 } from "./palette";
 export type * from "./types";
@@ -0,0 +1,113 @@
 import Color from "colorjs.io/dist/color.js";
 import type { ColourCoordinates, ColourInput, ColourValue } from "./types";
 export const EPSILON = 1e-9;
 export function clamp(value: number, minimum = 0, maximum = 1): number {
  return Math.min(maximum, Math.max(minimum, value));
 }
 export function round(value: number, precision = 4): number {
  const factor = 10 ** precision;
  const result = Math.round((value + Number.EPSILON) * factor) / factor;
  return Object.is(result, -0) ? 0 : result;
 }
 export function numberText(value: number, precision = 4): string {
  return String(round(value, precision));
 }
 export function alphaText(alpha: number, precision = 3): string {
  return numberText(clamp(alpha), precision);
 }
 export function finiteCoordinate(value: number | null | undefined): number {
  return typeof value === "number" && Number.isFinite(value) ? value : 0;
 }
 export function toColourValue(color: Color): ColourValue {
  return {
    space: color.spaceId,
    coords: color.coords.map(finiteCoordinate) as ColourCoordinates,
    alpha: clamp(Number.isFinite(color.alpha) ? color.alpha : 1),
  };
 }
 export function isColourValue(value: unknown): value is ColourValue {
  if (typeof value !== "object" || value === null) return false;
  const candidate = value as Partial<ColourValue>;
  return (
    typeof candidate.space === "string" &&
    Array.isArray(candidate.coords) &&
    candidate.coords.length === 3 &&
    candidate.coords.every(
      (coordinate) =>
        typeof coordinate === "number" && Number.isFinite(coordinate),
    ) &&
    typeof candidate.alpha === "number" &&
    Number.isFinite(candidate.alpha)
  );
 }
 export function asColor(input: ColourInput): Color {
  if (typeof input === "string") return new Color(input);
  return new Color(input.space, [...input.coords], clamp(input.alpha));
 }
 export function colorFrom(
  space: string,
  coords: readonly number[],
  alpha = 1,
 ): Color {
  return new Color(
    space,
    coords.map(finiteCoordinate) as ColourCoordinates,
    clamp(alpha),
  );
 }
 export function copyColour(value: ColourValue): ColourValue {
  return { space: value.space, coords: [...value.coords], alpha: value.alpha };
 }
 export function mappedColor(
  input: ColourInput,
  target = "srgb",
  method: "oklch.c" | "clip" = "oklch.c",
 ): Color {
  const converted = asColor(input).to(target);
  return converted.inGamut(target)
    ? converted
    : converted.toGamut({ space: target, method });
 }
 export function srgbChannels(
  input: ColourInput,
  map = true,
 ): ColourCoordinates {
  const color = map ? mappedColor(input, "srgb") : asColor(input).to("srgb");
  return color.coords.map((coordinate) =>
    map ? clamp(finiteCoordinate(coordinate)) : finiteCoordinate(coordinate),
  ) as ColourCoordinates;
 }
 export function lineariseSrgb(channel: number): number {
  return channel <= 0.04045
    ? channel / 12.92
    : ((channel + 0.055) / 1.055) ** 2.4;
 }
 export function encodeSrgb(channel: number): number {
  return channel <= 0.0031308
    ? 12.92 * channel
    : 1.055 * channel ** (1 / 2.4) - 0.055;
 }
 export function hueIndex(space: string): number | undefined {
  if (["hsl", "hsv", "hwb", "okhsl", "okhsv"].includes(space)) return 0;
  if (["lch", "oklch", "jzczhz", "hct"].includes(space)) return 2;
  return undefined;
 }
 export { Color };
@@ -0,0 +1,170 @@
 import { asColor, clamp, colorFrom, hueIndex, toColourValue } from "./internal";
 import { formatColour, toSrgbCss } from "./format";
 import { parseColour } from "./parse";
 import type {
  ColourCoordinates,
  ColourStop,
  ColourValue,
  EasingName,
  HueInterpolation,
  InterpolationOptions,
  InterpolationStep,
 } from "./types";
 interface PositionedStop {
  colour: ColourValue;
  position: number;
 }
 function ease(value: number, name: EasingName): number {
  switch (name) {
    case "ease-in":
      return value * value;
    case "ease-out":
      return 1 - (1 - value) ** 2;
    case "ease-in-out":
      return value < 0.5 ? 2 * value * value : 1 - (-2 * value + 2) ** 2 / 2;
    case "smoothstep":
      return value * value * (3 - 2 * value);
    case "linear":
      return value;
  }
 }
 function normaliseStops(
  stops: readonly ColourStop[],
  shouldClamp: boolean,
 ): PositionedStop[] {
  if (stops.length < 2)
    throw new RangeError("At least two colour stops are required.");
  const positions = stops.map((stop) => {
    if (stop.position === undefined) return undefined;
    if (!Number.isFinite(stop.position))
      throw new RangeError("Stop positions must be finite numbers.");
    return shouldClamp ? clamp(stop.position) : stop.position;
  });
  positions[0] ??= 0;
  positions[positions.length - 1] ??= 1;
  let previousKnown = 0;
  for (let index = 1; index < positions.length; index += 1) {
    if (positions[index] === undefined) continue;
    const start = positions[previousKnown] ?? 0;
    const end = Math.max(start, positions[index] ?? start);
    positions[index] = end;
    const gap = index - previousKnown;
    for (let missing = 1; missing < gap; missing += 1) {
      positions[previousKnown + missing] =
        start + ((end - start) * missing) / gap;
    }
    previousKnown = index;
  }
  return stops.map((stop, index) => ({
    colour: parseColour(stop.colour),
    position: positions[index] ?? 0,
  }));
 }
 function hueDelta(from: number, to: number, method: HueInterpolation): number {
  if (method === "raw") return to - from;
  const increasing = (((to - from) % 360) + 360) % 360;
  const decreasing = increasing === 0 ? 0 : increasing - 360;
  if (method === "increasing") return increasing;
  if (method === "decreasing") return decreasing;
  if (method === "shorter") return increasing <= 180 ? increasing : decreasing;
  if (increasing === 0) return 360;
  return increasing <= 180 ? decreasing : increasing;
 }
 export function interpolateColourStops(
  stops: readonly ColourStop[],
  position: number,
  options: InterpolationOptions = {},
 ): ColourValue {
  if (!Number.isFinite(position))
    throw new RangeError("Interpolation position must be finite.");
  const shouldClamp = options.clamp ?? true;
  const prepared = normaliseStops(stops, shouldClamp);
  const sample = shouldClamp ? clamp(position) : position;
  let left = prepared[0];
  let right = prepared[prepared.length - 1];
  if (!left || !right)
    throw new RangeError("At least two colour stops are required.");
  if (sample <= left.position) right = prepared[1] ?? right;
  else if (sample >= right.position)
    left = prepared[prepared.length - 2] ?? left;
  else {
    for (let index = 1; index < prepared.length; index += 1) {
      const candidate = prepared[index];
      if (candidate && sample <= candidate.position) {
        left = prepared[index - 1] ?? left;
        right = candidate;
        break;
      }
    }
  }
  const range = right.position - left.position;
  const local = range === 0 ? 1 : (sample - left.position) / range;
  const progress = ease(
    shouldClamp ? clamp(local) : local,
    options.easing ?? "linear",
  );
  const space = options.space ?? "oklch";
  const leftColor = asColor(left.colour).to(space);
  const rightColor = asColor(right.colour).to(space);
  const leftCoords = leftColor.coords.map((coordinate) =>
    Number(coordinate ?? 0),
  ) as ColourCoordinates;
  const rightCoords = rightColor.coords.map((coordinate) =>
    Number(coordinate ?? 0),
  ) as ColourCoordinates;
  const hueCoordinate = hueIndex(space);
  const alpha =
    left.colour.alpha + (right.colour.alpha - left.colour.alpha) * progress;
  const premultiplied = options.premultiplied ?? true;
  const coords = leftCoords.map((coordinate, index) => {
    if (index === hueCoordinate) {
      return (
        coordinate +
        hueDelta(
          coordinate,
          rightCoords[index] ?? coordinate,
          options.hue ?? "shorter",
        ) *
          progress
      );
    }
    const rightCoordinate = rightCoords[index] ?? coordinate;
    if (!premultiplied) {
      return coordinate + (rightCoordinate - coordinate) * progress;
    }
    const mixed =
      coordinate * left.colour.alpha * (1 - progress) +
      rightCoordinate * right.colour.alpha * progress;
    return alpha > 1e-12 ? mixed / alpha : 0;
  }) as ColourCoordinates;
  return toColourValue(colorFrom(space, coords, alpha));
 }
 export function interpolateStops(
  stops: readonly ColourStop[],
  count: number,
  options: InterpolationOptions = {},
 ): InterpolationStep[] {
  if (!Number.isInteger(count) || count < 2 || count > 10_000) {
    throw new RangeError("Step count must be an integer from 2 to 10,000.");
  }
  return Array.from({ length: count }, (_, index) => {
    const position = index / (count - 1);
    const colour = interpolateColourStops(stops, position, options);
    return {
      position,
      colour,
      css: toSrgbCss(colour),
      hex: formatColour(colour, colour.alpha < 1 ? "hex8" : "hex"),
    };
  });
 }
@@ -0,0 +1,332 @@
 import { asColor, clamp, colorFrom, toColourValue } from "./internal";
 import { formatColour } from "./format";
 import { mapToGamut } from "./gamut";
 import { interpolateColourStops } from "./interpolate";
 import { parseColour, tryParseColour } from "./parse";
 import type {
  ColourFormat,
  ColourInput,
  ColourValue,
  HarmonyType,
  PaletteEntry,
  PaletteExportFormat,
  PaletteExportOptions,
  PaletteScaleOptions,
 } from "./types";
 const HARMONY_OFFSETS: Record<HarmonyType, readonly number[]> = {
  complementary: [0, 180],
  analogous: [-30, 0, 30],
  "split-complementary": [0, 150, 210],
  triadic: [0, 120, 240],
  tetradic: [0, 60, 180, 240],
  square: [0, 90, 180, 270],
 };
 export function colourHarmony(
  input: ColourInput,
  type: HarmonyType,
 ): ColourValue[] {
  const source = parseColour(input);
  const converted = asColor(source).to("oklch");
  const lightness = Number(converted.coords[0] ?? 0);
  const chroma = Number(converted.coords[1] ?? 0);
  const hue = Number(converted.coords[2] ?? 0);
  return HARMONY_OFFSETS[type].map((offset) =>
    mapToGamut(
      toColourValue(
        colorFrom(
          "oklch",
          [lightness, chroma, (hue + offset + 360) % 360],
          source.alpha,
        ),
      ),
    ),
  );
 }
 export const generateHarmony = colourHarmony;
 function scale(
  input: ColourInput,
  endpoint: ColourInput,
  count: number,
  options: PaletteScaleOptions,
 ): ColourValue[] {
  if (!Number.isInteger(count) || count < 1 || count > 1_000) {
    throw new RangeError("Palette count must be an integer from 1 to 1,000.");
  }
  const source = parseColour(input);
  const values: ColourValue[] = options.includeBase ? [source] : [];
  const includeEndpoint = options.includeEndpoint ?? false;
  const denominator = includeEndpoint ? count : count + 1;
  for (let index = 1; index <= count; index += 1) {
    values.push(
      interpolateColourStops(
        [{ colour: source }, { colour: endpoint }],
        index / denominator,
        { space: options.space ?? "oklab" },
      ),
    );
  }
  return values;
 }
 export function tints(
  input: ColourInput,
  count = 5,
  options: PaletteScaleOptions = {},
 ): ColourValue[] {
  return scale(input, "#ffffff", count, options);
 }
 export function shades(
  input: ColourInput,
  count = 5,
  options: PaletteScaleOptions = {},
 ): ColourValue[] {
  return scale(input, "#000000", count, options);
 }
 export function tones(
  input: ColourInput,
  count = 5,
  options: PaletteScaleOptions = {},
 ): ColourValue[] {
  const source = parseColour(input);
  const lightness = clamp(Number(asColor(source).to("oklab").coords[0] ?? 0));
  const neutral = toColourValue(
    colorFrom("oklab", [lightness, 0, 0], source.alpha),
  );
  return scale(source, neutral, count, options);
 }
 function entryFromUnknown(
  name: string,
  value: unknown,
 ): PaletteEntry | undefined {
  const candidate =
    typeof value === "object" && value !== null
      ? ((value as Record<string, unknown>).$value ??
        (value as Record<string, unknown>).value ??
        (value as Record<string, unknown>).colour ??
        (value as Record<string, unknown>).color)
      : value;
  if (typeof candidate !== "string") return undefined;
  const result = tryParseColour(candidate);
  return result.ok
    ? { name, colour: result.value, source: candidate }
    : undefined;
 }
 function parseJsonPalette(input: string): PaletteEntry[] | undefined {
  let parsed: unknown;
  try {
    parsed = JSON.parse(input) as unknown;
  } catch {
    return undefined;
  }
  if (Array.isArray(parsed)) {
    return parsed.map((item, index) => {
      if (typeof item === "string")
        return {
          name: `colour-${index + 1}`,
          colour: parseColour(item),
          source: item,
        };
      if (typeof item !== "object" || item === null)
        throw new TypeError(`Palette item ${index + 1} is invalid.`);
      const record = item as Record<string, unknown>;
      const name =
        typeof record.name === "string" ? record.name : `colour-${index + 1}`;
      const entry = entryFromUnknown(name, record);
      if (!entry)
        throw new TypeError(
          `Palette item “${name}” does not contain a valid colour.`,
        );
      return entry;
    });
  }
  if (typeof parsed === "object" && parsed !== null) {
    const entries: PaletteEntry[] = [];
    const visit = (record: Record<string, unknown>, path: string[]): void => {
      for (const [name, value] of Object.entries(record)) {
        if (name.startsWith("$")) continue;
        const nextPath = [...path, name];
        const entry = entryFromUnknown(nextPath.join("-"), value);
        if (entry) entries.push(entry);
        else if (
          typeof value === "object" &&
          value !== null &&
          !Array.isArray(value)
        ) {
          visit(value as Record<string, unknown>, nextPath);
        }
      }
    };
    visit(parsed as Record<string, unknown>, []);
    if (entries.length > 0) return entries;
  }
  return undefined;
 }
 export function parsePaletteList(input: string): PaletteEntry[] {
  const trimmed = input.trim();
  if (!trimmed) return [];
  const json = parseJsonPalette(trimmed);
  if (json) return json;
  const cssBlock = trimmed.match(/^\s*(?::root|[^{}]+)\s*\{([\s\S]*)\}\s*$/);
  const listText = cssBlock?.[1] ?? trimmed;
  const lines = listText
    .split(/[\n;]/)
    .map((line) => line.trim().replace(/,$/, ""))
    .filter(Boolean);
  return lines.map((line, index) => {
    const whole = tryParseColour(line);
    if (whole.ok)
      return { name: `colour-${index + 1}`, colour: whole.value, source: line };
    const match = line.match(/^(--)?([^:=]+?)\s*[:=]\s*(.+)$/);
    if (!match)
      throw new TypeError(`Could not parse palette line ${index + 1}: ${line}`);
    const name = (match[2] ?? `colour-${index + 1}`).trim();
    const source = (match[3] ?? "").trim();
    return { name, colour: parseColour(source), source };
  });
 }
 export const parseNamedColourList = parsePaletteList;
 export function normaliseTokenName(input: string): string {
  const normalised = input
    .normalize("NFKD")
    .replace(/[\u0300-\u036f]/g, "")
    .trim()
    .toLowerCase()
    .replace(/[^a-z0-9_-]+/g, "-")
    .replace(/^-+|-+$/g, "")
    .replace(/-{2,}/g, "-");
  return normalised || "colour";
 }
 function outputValue(entry: PaletteEntry, format: ColourFormat): string {
  return formatColour(
    entry.colour,
    format === "hex" && entry.colour.alpha < 1 ? "hex8" : format,
  );
 }
 function uniqueNames(
  entries: readonly PaletteEntry[],
 ): Array<{ name: string; entry: PaletteEntry }> {
  const used = new Map<string, number>();
  return entries.map((entry) => {
    const base = normaliseTokenName(entry.name);
    const occurrence = (used.get(base) ?? 0) + 1;
    used.set(base, occurrence);
    return { name: occurrence === 1 ? base : `${base}-${occurrence}`, entry };
  });
 }
 export function exportCssVariables(
  entries: readonly PaletteEntry[],
  options: PaletteExportOptions = {},
 ): string {
  const prefix = normaliseTokenName(options.prefix ?? "colour");
  const lines = uniqueNames(entries).map(
    ({ name, entry }) =>
      `  --${prefix}-${name}: ${outputValue(entry, options.format ?? "hex")};`,
  );
  return `:root {\n${lines.join("\n")}\n}`;
 }
 export function exportScssVariables(
  entries: readonly PaletteEntry[],
  options: PaletteExportOptions = {},
 ): string {
  const prefix = normaliseTokenName(options.prefix ?? "colour");
  return uniqueNames(entries)
    .map(
      ({ name, entry }) =>
        `$${prefix}-${name}: ${outputValue(entry, options.format ?? "hex")};`,
    )
    .join("\n");
 }
 export function exportJsonPalette(
  entries: readonly PaletteEntry[],
  options: PaletteExportOptions = {},
 ): string {
  const value = Object.fromEntries(
    uniqueNames(entries).map(({ name, entry }) => [
      name,
      outputValue(entry, options.format ?? "hex"),
    ]),
  );
  return JSON.stringify(value, null, options.pretty === false ? undefined : 2);
 }
 export function exportDesignTokens(
  entries: readonly PaletteEntry[],
  options: PaletteExportOptions = {},
 ): string {
  const value = Object.fromEntries(
    uniqueNames(entries).map(({ name, entry }) => [
      name,
      { $type: "color", $value: outputValue(entry, options.format ?? "hex") },
    ]),
  );
  return JSON.stringify(value, null, options.pretty === false ? undefined : 2);
 }
 export function exportTailwindPalette(
  entries: readonly PaletteEntry[],
  options: PaletteExportOptions = {},
 ): string {
  const value = Object.fromEntries(
    uniqueNames(entries).map(({ name, entry }) => [
      name,
      outputValue(entry, options.format ?? "hex"),
    ]),
  );
  return `export default ${JSON.stringify(value, null, options.pretty === false ? undefined : 2)};`;
 }
 function csvCell(value: string): string {
  return /[",\r\n]/.test(value) ? `"${value.replace(/"/g, '""')}"` : value;
 }
 export function exportCsvPalette(
  entries: readonly PaletteEntry[],
  options: PaletteExportOptions = {},
 ): string {
  return [
    "name,value",
    ...uniqueNames(entries).map(
      ({ name, entry }) =>
        `${csvCell(name)},${csvCell(outputValue(entry, options.format ?? "hex"))}`,
    ),
  ].join("\n");
 }
 export function exportPalette(
  entries: readonly PaletteEntry[],
  format: PaletteExportFormat = "css",
  options: PaletteExportOptions = {},
 ): string {
  switch (format) {
    case "css":
      return exportCssVariables(entries, options);
    case "scss":
      return exportScssVariables(entries, options);
    case "json":
      return exportJsonPalette(entries, options);
    case "tokens":
      return exportDesignTokens(entries, options);
    case "tailwind":
      return exportTailwindPalette(entries, options);
    case "csv":
      return exportCsvPalette(entries, options);
  }
 }
@@ -0,0 +1,320 @@
 import {
  Color,
  clamp,
  copyColour,
  isColourValue,
  toColourValue,
 } from "./internal";
 import type {
  ColourInput,
  ColourParseErrorCode,
  ColourParseResult,
  ColourValue,
 } from "./types";
 export class ColourParseError extends Error {
  readonly code: ColourParseErrorCode;
  readonly input: string;
  constructor(code: ColourParseErrorCode, message: string, input: string) {
    super(message);
    this.name = "ColourParseError";
    this.code = code;
    this.input = input;
  }
 }
 function parseNumber(token: string, label: string, input: string): number {
  const value = Number(token);
  if (!Number.isFinite(value)) {
    throw new ColourParseError(
      "non-finite",
      `${label} must be a finite number.`,
      input,
    );
  }
  return value;
 }
 function parseUnitInterval(
  token: string,
  label: string,
  input: string,
  allowHundred = true,
 ): number {
  const trimmed = token.trim();
  const percentage = trimmed.endsWith("%");
  const value = parseNumber(
    percentage ? trimmed.slice(0, -1) : trimmed,
    label,
    input,
  );
  const normalised =
    percentage || (allowHundred && value > 1) ? value / 100 : value;
  if (normalised < 0 || normalised > 1) {
    throw new ColourParseError(
      "out-of-range",
      `${label} must be between 0 and 100%.`,
      input,
    );
  }
  return normalised;
 }
 function parseAlpha(token: string | undefined, input: string): number {
  return token === undefined
    ? 1
    : parseUnitInterval(token, "Alpha", input, false);
 }
 function parseAngle(token: string, input: string): number {
  const match = token
    .trim()
    .match(
      /^([+-]?(?:\d+(?:\.\d*)?|\.\d+)(?:e[+-]?\d+)?)(deg|grad|rad|turn)?$/i,
    );
  if (!match)
    throw new ColourParseError(
      "invalid-syntax",
      "Hue must be a valid CSS angle.",
      input,
    );
  const value = parseNumber(match[1] ?? "", "Hue", input);
  const unit = match[2]?.toLowerCase() ?? "deg";
  const degrees =
    unit === "turn"
      ? value * 360
      : unit === "rad"
        ? (value * 180) / Math.PI
        : unit === "grad"
          ? value * 0.9
          : value;
  return ((degrees % 360) + 360) % 360;
 }
 function functionParts(
  body: string,
  expectedChannels = 3,
 ): { channels: string[]; alpha?: string } {
  const slash = body.split("/");
  if (slash.length > 2) return { channels: [] };
  const channelText = slash[0]?.trim() ?? "";
  const commaParts = channelText.includes(",")
    ? channelText.split(",").map((part) => part.trim())
    : channelText.split(/\s+/).filter(Boolean);
  let alpha = slash[1]?.trim();
  if (commaParts.length === expectedChannels + 1 && alpha === undefined)
    alpha = commaParts.pop();
  return { channels: commaParts, ...(alpha === undefined ? {} : { alpha }) };
 }
 function parseHsv(input: string): ColourValue | undefined {
  const match = input.match(/^hs(?:v|b)a?\((.*)\)$/is);
  if (!match) return undefined;
  const parts = functionParts(match[1] ?? "");
  if (parts.channels.length !== 3) {
    throw new ColourParseError(
      "invalid-syntax",
      "HSV needs hue, saturation and value channels.",
      input,
    );
  }
  const hue = parseAngle(parts.channels[0] ?? "", input);
  const saturation =
    parseUnitInterval(parts.channels[1] ?? "", "Saturation", input) * 100;
  const value =
    parseUnitInterval(parts.channels[2] ?? "", "Value", input) * 100;
  return {
    space: "hsv",
    coords: [hue, saturation, value],
    alpha: parseAlpha(parts.alpha, input),
  };
 }
 function parseCmyk(input: string): ColourValue | undefined {
  const match = input.match(/^(?:device-)?cmyka?\((.*)\)$/is);
  if (!match) return undefined;
  const parts = functionParts(match[1] ?? "", 4);
  if (parts.channels.length !== 4) {
    throw new ColourParseError(
      "invalid-syntax",
      "CMYK needs cyan, magenta, yellow and black channels.",
      input,
    );
  }
  const [cyan, magenta, yellow, black] = parts.channels.map((part, index) =>
    parseUnitInterval(
      part,
      ["Cyan", "Magenta", "Yellow", "Black"][index] ?? "Channel",
      input,
    ),
  );
  const c = cyan ?? 0;
  const m = magenta ?? 0;
  const y = yellow ?? 0;
  const k = black ?? 0;
  return {
    space: "srgb",
    coords: [(1 - c) * (1 - k), (1 - m) * (1 - k), (1 - y) * (1 - k)],
    alpha: parseAlpha(parts.alpha, input),
  };
 }
 function parseBareRgb(input: string): ColourValue | undefined {
  if (!/^\s*[+-]?(?:\d|\.)/.test(input) || !input.includes(","))
    return undefined;
  const parts = input.split(",").map((part) => part.trim());
  if (parts.length < 3 || parts.length > 4 || parts.some((part) => part === ""))
    return undefined;
  const channels = parts.slice(0, 3).map((part, index) => {
    const value = parseNumber(
      part,
      ["Red", "Green", "Blue"][index] ?? "Channel",
      input,
    );
    if (value < 0 || value > 255) {
      throw new ColourParseError(
        "out-of-range",
        "RGB channels must be between 0 and 255.",
        input,
      );
    }
    return value / 255;
  });
  return {
    space: "srgb",
    coords: channels as [number, number, number],
    alpha: parseAlpha(parts[3], input),
  };
 }
 function normaliseStringInput(input: string): string {
  const trimmed = input.trim();
  if (/^[\da-f]{3,8}$/i.test(trimmed) && [3, 4, 6, 8].includes(trimmed.length))
    return `#${trimmed}`;
  if (/^0x[\da-f]{6,8}$/i.test(trimmed)) return `#${trimmed.slice(2)}`;
  return trimmed;
 }
 export function parseColour(input: ColourInput): ColourValue {
  if (typeof input !== "string") {
    if (!isColourValue(input)) {
      throw new ColourParseError(
        "invalid-syntax",
        "Colour value is malformed.",
        String(input),
      );
    }
    if (input.alpha < 0 || input.alpha > 1) {
      throw new ColourParseError(
        "out-of-range",
        "Alpha must be between 0 and 1.",
        JSON.stringify(input),
      );
    }
    try {
      // Validate the public space identifier before returning a defensive copy.
      new Color(input.space, [...input.coords], clamp(input.alpha));
      return copyColour(input);
    } catch (error) {
      throw new ColourParseError(
        "unsupported-space",
        error instanceof Error ? error.message : "Unsupported colour space.",
        JSON.stringify(input),
      );
    }
  }
  const text = normaliseStringInput(input);
  if (text === "")
    throw new ColourParseError("empty", "Enter a colour.", input);
  const custom = parseHsv(text) ?? parseCmyk(text) ?? parseBareRgb(text);
  if (custom) return custom;
  try {
    return toColourValue(new Color(text));
  } catch (error) {
    const detail =
      error instanceof Error && error.message ? ` ${error.message}` : "";
    throw new ColourParseError(
      "invalid-syntax",
      `Could not parse “${text}”.${detail}`,
      input,
    );
  }
 }
 export function tryParseColour(input: ColourInput): ColourParseResult {
  try {
    return { ok: true, value: parseColour(input) };
  } catch (error) {
    if (error instanceof ColourParseError) {
      return {
        ok: false,
        error: { code: error.code, message: error.message, input: error.input },
      };
    }
    return {
      ok: false,
      error: {
        code: "invalid-syntax",
        message: "Could not parse this colour.",
        input: String(input),
      },
    };
  }
 }
 function splitTopLevel(input: string): string[] {
  const output: string[] = [];
  let start = 0;
  let depth = 0;
  let quote = "";
  for (let index = 0; index < input.length; index += 1) {
    const character = input[index] ?? "";
    if (quote) {
      if (character === quote && input[index - 1] !== "\\") quote = "";
      continue;
    }
    if (character === '"' || character === "'") quote = character;
    else if (character === "(") depth += 1;
    else if (character === ")") depth = Math.max(0, depth - 1);
    else if (
      depth === 0 &&
      (character === "\n" || character === ";" || character === ",")
    ) {
      const part = input.slice(start, index).trim();
      if (part) output.push(part);
      start = index + 1;
    }
  }
  const last = input.slice(start).trim();
  if (last) output.push(last);
  return output;
 }
 export function parseColourList(input: string): ColourValue[] {
  const trimmed = input.trim();
  if (!trimmed) return [];
  const whole = tryParseColour(trimmed);
  if (whole.ok) return [whole.value];
  let values: unknown;
  try {
    values = JSON.parse(trimmed) as unknown;
  } catch {
    values = undefined;
  }
  if (Array.isArray(values)) {
    return values.map((value) =>
      parseColour(typeof value === "string" ? value : (value as ColourValue)),
    );
  }
  const parts = splitTopLevel(trimmed);
  if (parts.length <= 1)
    throw new ColourParseError(whole.error.code, whole.error.message, input);
  return parts.map(parseColour);
 }
@@ -0,0 +1,249 @@
 export type ColourCoordinates = [number, number, number];
 /** A serialisable colour value. Coordinates use Color.js space conventions. */
 export interface ColourValue {
  space: string;
  coords: ColourCoordinates;
  alpha: number;
 }
 export type ColourInput = string | ColourValue;
 export type ColourParseErrorCode =
  | "empty"
  | "invalid-syntax"
  | "unsupported-space"
  | "non-finite"
  | "out-of-range";
 export interface ColourParseFailure {
  ok: false;
  error: {
    code: ColourParseErrorCode;
    message: string;
    input: string;
  };
 }
 export interface ColourParseSuccess {
  ok: true;
  value: ColourValue;
 }
 export type ColourParseResult = ColourParseSuccess | ColourParseFailure;
 export type ColourFormat =
  | "hex"
  | "hex8"
  | "rgb"
  | "rgba"
  | "hsl"
  | "hsv"
  | "hwb"
  | "cmyk"
  | "lab"
  | "lch"
  | "oklab"
  | "oklch"
  | "p3"
  | "rec2020"
  | "a98rgb"
  | "prophoto"
  | "xyz-d50"
  | "xyz-d65"
  | "css";
 export interface FormatColourOptions {
  precision?: number;
  mapToSrgb?: boolean;
  includeAlpha?: boolean;
 }
 export interface ConversionRow {
  id: ColourFormat;
  label: string;
  value: string;
  copyValue: string;
 }
 export interface SrgbPreview {
  css: string;
  hex: string;
  rgb: ColourCoordinates;
  alpha: number;
  wasMapped: boolean;
 }
 export type GamutMappingMethod = "oklch-chroma" | "clip";
 export interface GamutMappingOptions {
  target?: string;
  method?: GamutMappingMethod;
 }
 export interface GamutSpaceReport {
  space: string;
  label: string;
  inGamut: boolean;
  mapped: ColourValue;
  mappedCss: string;
  deltaEOK: number;
 }
 export interface GamutReport {
  source: ColourValue;
  spaces: GamutSpaceReport[];
 }
 export type BlendMode =
  | "normal"
  | "multiply"
  | "screen"
  | "overlay"
  | "darken"
  | "lighten"
  | "color-dodge"
  | "color-burn"
  | "hard-light"
  | "soft-light"
  | "difference"
  | "exclusion"
  | "hue"
  | "saturation"
  | "color"
  | "luminosity";
 export type CompositingSpace = "srgb" | "linear-srgb";
 export interface CompositeLayer {
  colour: ColourInput;
  opacity?: number;
  blendMode?: BlendMode;
  name?: string;
 }
 export interface CompositeOptions {
  space?: CompositingSpace;
  /** Array order. The default models a paint stack from its background upwards. */
  order?: "bottom-to-top" | "top-to-bottom";
 }
 export interface SourceOverOptions {
  space?: CompositingSpace;
  blendMode?: BlendMode;
  /** Additional source opacity, multiplied with its own alpha. */
  opacity?: number;
 }
 export interface CompositeResult {
  colour: ColourValue;
  css: string;
  hex: string;
 }
 export interface ColourStop {
  colour: ColourInput;
  /** Normalised position. Missing positions are distributed like a CSS gradient. */
  position?: number;
  name?: string;
 }
 export type InterpolationSpace =
  | "srgb"
  | "srgb-linear"
  | "hsl"
  | "hsv"
  | "lab"
  | "lch"
  | "oklab"
  | "oklch"
  | "p3";
 export type HueInterpolation =
  "shorter" | "longer" | "increasing" | "decreasing" | "raw";
 export type EasingName =
  "linear" | "ease-in" | "ease-out" | "ease-in-out" | "smoothstep";
 export interface InterpolationOptions {
  space?: InterpolationSpace;
  hue?: HueInterpolation;
  easing?: EasingName;
  clamp?: boolean;
  /** Interpolate premultiplied components to avoid transparent-colour fringes. Defaults to true. */
  premultiplied?: boolean;
 }
 export interface InterpolationStep {
  position: number;
  colour: ColourValue;
  css: string;
  hex: string;
 }
 export interface ContrastOptions {
  /** Canvas below a translucent background. Defaults to white. */
  canvas?: ColourInput;
 }
 export interface ContrastReport {
  ratio: number;
  foreground: ColourValue;
  background: ColourValue;
  flattenedForeground: ColourValue;
  flattenedBackground: ColourValue;
  passes: {
    aaLarge: boolean;
    aaaLarge: boolean;
    aaNormal: boolean;
    aaaNormal: boolean;
    nonText: boolean;
  };
 }
 export interface ContrastSuggestion {
  colour: ColourValue;
  css: string;
  hex: string;
  ratio: number;
  deltaEOK: number;
  direction: "lighter" | "darker";
 }
 export type DeltaEMethod = "76" | "cmc" | "2000" | "ok" | "itp" | "jz";
 export type ColourVisionDeficiency =
  "protanopia" | "deuteranopia" | "tritanopia" | "achromatopsia";
 export interface ColourVisionOptions {
  severity?: number;
  mapToSrgb?: boolean;
 }
 export type HarmonyType =
  | "complementary"
  | "analogous"
  | "split-complementary"
  | "triadic"
  | "tetradic"
  | "square";
 export interface PaletteEntry {
  name: string;
  colour: ColourValue;
  source?: string;
 }
 export type PaletteExportFormat =
  "css" | "scss" | "json" | "tokens" | "tailwind" | "csv";
 export interface PaletteExportOptions {
  format?: ColourFormat;
  prefix?: string;
  pretty?: boolean;
 }
 export interface PaletteScaleOptions {
  includeBase?: boolean;
  includeEndpoint?: boolean;
  space?: InterpolationSpace;
 }
@@ -0,0 +1,35 @@
 import { Component, type ErrorInfo, type ReactNode } from "react";
 interface Props {
  children: ReactNode;
 }
 interface State {
  error: Error | null;
 }
 export class AppErrorBoundary extends Component<Props, State> {
  state: State = { error: null };
  static getDerivedStateFromError(error: Error): State {
    return { error };
  }
  componentDidCatch(error: Error, info: ErrorInfo): void {
    console.error("Colour Tools encountered an interface error", error, info);
  }
  render(): ReactNode {
    if (!this.state.error) return this.props.children;
    return (
      <main className="fatal-error" role="alert">
        <h1>Colour Tools could not continue</h1>
        <p>{this.state.error.message}</p>
        <button type="button" onClick={() => globalThis.location.reload()}>
          Reload application
        </button>
      </main>
    );
  }
 }
@@ -0,0 +1,53 @@
 import { toSrgbPreview, tryParseColour } from "../colour";
 interface ColourFieldProps {
  id: string;
  label: string;
  value: string;
  onChange: (value: string) => void;
  description?: string;
  compact?: boolean;
 }
 export function ColourField({
  id,
  label,
  value,
  onChange,
  description,
  compact,
 }: ColourFieldProps) {
  const result = tryParseColour(value);
  const preview = result.ok ? toSrgbPreview(result.value).css : "transparent";
  const errorId = `${id}-error`;
  return (
    <div className={`field colour-field${compact ? " is-compact" : ""}`}>
      <label className="field-label" htmlFor={id}>
        {label}
      </label>
      <span className="colour-input-shell">
        <span
          className="mini-swatch checkerboard"
          style={{ "--swatch": preview } as React.CSSProperties}
          aria-hidden="true"
        />
        <input
          id={id}
          value={value}
          onChange={(event) => onChange(event.target.value)}
          spellCheck={false}
          autoComplete="off"
          aria-invalid={!result.ok}
          aria-describedby={!result.ok ? errorId : undefined}
        />
      </span>
      {description && <span className="field-help">{description}</span>}
      {!result.ok && (
        <span id={errorId} className="field-error" role="status">
          {result.error.message}
        </span>
      )}
    </div>
  );
 }
@@ -0,0 +1,401 @@
 import { useMemo, useState, type DragEvent } from "react";
 import {
  compositeLayers,
  toSrgbPreview,
  tryParseColour,
  type BlendMode,
  type CompositingSpace,
 } from "../colour";
 import { ColourField } from "./ColourField";
 import { CopyButton } from "./CopyButton";
 interface LayerState {
  id: string;
  name: string;
  colour: string;
  opacity: number;
  blendMode: BlendMode;
  enabled: boolean;
 }
 const BLEND_MODES: BlendMode[] = [
  "normal",
  "multiply",
  "screen",
  "overlay",
  "darken",
  "lighten",
  "color-dodge",
  "color-burn",
  "hard-light",
  "soft-light",
  "difference",
  "exclusion",
  "hue",
  "saturation",
  "color",
  "luminosity",
 ];
 let layerSequence = 4;
 const makeLayer = (
  colour = "rgb(80 110 255 / 55%)",
  name?: string,
 ): LayerState => ({
  id: `layer-${layerSequence++}`,
  name: name ?? `Layer ${layerSequence - 1}`,
  colour,
  opacity: 1,
  blendMode: "normal",
  enabled: true,
 });
 export function CompositeLab({
  onAddColour,
 }: {
  onAddColour: (colour: string, name?: string) => void;
 }) {
  const [layers, setLayers] = useState<LayerState[]>([
    { ...makeLayer("rgb(240 52 89 / 65%)", "Rose"), id: "layer-1" },
    { ...makeLayer("rgb(36 128 255 / 55%)", "Blue"), id: "layer-2" },
    { ...makeLayer("rgb(250 196 65 / 45%)", "Gold"), id: "layer-3" },
  ]);
  const [matte, setMatte] = useState("#ffffff");
  const [flatten, setFlatten] = useState(true);
  const [space, setSpace] = useState<CompositingSpace>("srgb");
  const [dragging, setDragging] = useState<number | null>(null);
  const calculation = useMemo(() => {
    const inputs = layers
      .filter((layer) => layer.enabled)
      .map((layer) => ({
        colour: layer.colour,
        opacity: layer.opacity,
        blendMode: layer.blendMode,
        name: layer.name,
      }));
    if (flatten)
      inputs.push({
        colour: matte,
        opacity: 1,
        blendMode: "normal",
        name: "Matte",
      });
    if (inputs.length === 0)
      return { error: "Enable at least one layer.", result: null };
    if (inputs.some((layer) => !tryParseColour(layer.colour).ok)) {
      return {
        error: "Finish editing invalid layer colours to recalculate.",
        result: null,
      };
    }
    try {
      return {
        error: null,
        result: compositeLayers(inputs, { order: "top-to-bottom", space }),
      };
    } catch (error) {
      return {
        error:
          error instanceof Error
            ? error.message
            : "Could not composite these layers.",
        result: null,
      };
    }
  }, [flatten, layers, matte, space]);
  function updateLayer(id: string, update: Partial<LayerState>) {
    setLayers((current) =>
      current.map((layer) =>
        layer.id === id ? { ...layer, ...update } : layer,
      ),
    );
  }
  function moveLayer(from: number, to: number) {
    if (to < 0 || to >= layers.length || from === to) return;
    setLayers((current) => {
      const copy = [...current];
      const [item] = copy.splice(from, 1);
      if (!item) return current;
      copy.splice(to, 0, item);
      return copy;
    });
  }
  function drop(event: DragEvent, index: number) {
    event.preventDefault();
    if (dragging !== null) moveLayer(dragging, index);
    setDragging(null);
  }
  const preview = calculation.result
    ? toSrgbPreview(calculation.result.colour)
    : null;
  return (
    <div className="lab-stack">
      <header className="lab-heading">
        <div>
          <p className="eyebrow">Source-over, from two to many</p>
          <h2>Composite translucent colours</h2>
          <p>
            The first row is the topmost layer. Reorder, blend and flatten an
            arbitrary RGBA stack to an opaque RGB result.
          </p>
        </div>
        <label className="field compact-control">
          <span className="field-label">Working light</span>
          <select
            value={space}
            onChange={(event) =>
              setSpace(event.target.value as CompositingSpace)
            }
          >
            <option value="srgb">Encoded sRGB</option>
            <option value="linear-srgb">Linear-light sRGB</option>
          </select>
        </label>
      </header>
      <div className="composite-layout">
        <section className="panel layer-panel">
          <div className="section-heading">
            <div>
              <h3>Layer stack</h3>
              <p>
                Top to bottom · alpha in the colour and layer opacity are
                multiplied.
              </p>
            </div>
            <button
              type="button"
              onClick={() => setLayers((current) => [...current, makeLayer()])}
            >
              + Add layer
            </button>
          </div>
          <ol className="layer-list">
            {layers.map((layer, index) => {
              const parsed = tryParseColour(layer.colour);
              const layerPreview = parsed.ok
                ? toSrgbPreview(parsed.value).css
                : "transparent";
              return (
                <li
                  key={layer.id}
                  className={`layer-row${!layer.enabled ? " is-disabled" : ""}`}
                  draggable
                  onDragStart={(event) => {
                    setDragging(index);
                    event.dataTransfer.effectAllowed = "move";
                  }}
                  onDragEnd={() => setDragging(null)}
                  onDragOver={(event) => event.preventDefault()}
                  onDrop={(event) => drop(event, index)}
                >
                  <span
                    className="drag-handle"
                    title="Drag to reorder"
                    aria-hidden="true"
                  >
                    ⋮⋮
                  </span>
                  <span
                    className="layer-swatch checkerboard"
                    style={{ "--swatch": layerPreview } as React.CSSProperties}
                  />
                  <div className="layer-fields">
                    <label className="field">
                      <span className="field-label">Name</span>
                      <input
                        value={layer.name}
                        onChange={(event) =>
                          updateLayer(layer.id, { name: event.target.value })
                        }
                      />
                    </label>
                    <ColourField
                      id={`${layer.id}-colour`}
                      label="Colour"
                      value={layer.colour}
                      onChange={(colour) => updateLayer(layer.id, { colour })}
                      compact
                    />
                    <label className="field">
                      <span className="field-label">
                        Opacity · {Math.round(layer.opacity * 100)}%
                      </span>
                      <input
                        type="range"
                        min="0"
                        max="1"
                        step="0.01"
                        value={layer.opacity}
                        onChange={(event) =>
                          updateLayer(layer.id, {
                            opacity: Number(event.target.value),
                          })
                        }
                      />
                    </label>
                    <label className="field">
                      <span className="field-label">Blend</span>
                      <select
                        value={layer.blendMode}
                        onChange={(event) =>
                          updateLayer(layer.id, {
                            blendMode: event.target.value as BlendMode,
                          })
                        }
                      >
                        {BLEND_MODES.map((mode) => (
                          <option key={mode}>{mode}</option>
                        ))}
                      </select>
                    </label>
                  </div>
                  <div className="layer-actions">
                    <label className="toggle" title="Enable layer">
                      <input
                        type="checkbox"
                        checked={layer.enabled}
                        onChange={(event) =>
                          updateLayer(layer.id, {
                            enabled: event.target.checked,
                          })
                        }
                      />
                      <span className="sr-only">Enable {layer.name}</span>
                    </label>
                    <button
                      type="button"
                      className="icon-button"
                      disabled={index === 0}
                      onClick={() => moveLayer(index, index - 1)}
                      title="Move up"
                    >
                      ↑
                    </button>
                    <button
                      type="button"
                      className="icon-button"
                      disabled={index === layers.length - 1}
                      onClick={() => moveLayer(index, index + 1)}
                      title="Move down"
                    >
                      ↓
                    </button>
                    <button
                      type="button"
                      className="icon-button"
                      onClick={() =>
                        setLayers((current) => {
                          const copy = [...current];
                          copy.splice(index + 1, 0, {
                            ...layer,
                            id: `layer-${layerSequence++}`,
                            name: `${layer.name} copy`,
                          });
                          return copy;
                        })
                      }
                      title="Duplicate layer"
                    >
                      ⧉
                    </button>
                    <button
                      type="button"
                      className="icon-button danger"
                      disabled={layers.length === 1}
                      onClick={() =>
                        setLayers((current) =>
                          current.filter((item) => item.id !== layer.id),
                        )
                      }
                      title="Remove layer"
                    >
                      ×
                    </button>
                  </div>
                </li>
              );
            })}
          </ol>
          <div className="matte-row">
            <label className="toggle-label">
              <input
                type="checkbox"
                checked={flatten}
                onChange={(event) => setFlatten(event.target.checked)}
              />
              <span>
                <strong>Flatten over a matte</strong>
                <small>Produces an opaque RGB result</small>
              </span>
            </label>
            {flatten && (
              <ColourField
                id="matte-colour"
                label="Matte"
                value={matte}
                onChange={setMatte}
                compact
              />
            )}
          </div>
        </section>
        <aside className="panel result-panel">
          <p className="eyebrow">Result</p>
          <div className="composite-preview checkerboard">
            <div style={{ background: preview?.css ?? "transparent" }} />
          </div>
          {calculation.error && (
            <p className="field-error" role="status">
              {calculation.error}
            </p>
          )}
          {calculation.result && preview && (
            <>
              <div className="result-values">
                <div>
                  <span>CSS</span>
                  <code>{calculation.result.css}</code>
                  <CopyButton value={calculation.result.css} compact />
                </div>
                <div>
                  <span>Hex</span>
                  <code>{calculation.result.hex}</code>
                  <CopyButton value={calculation.result.hex} compact />
                </div>
                <div>
                  <span>Preview</span>
                  <code>{preview.css}</code>
                  <CopyButton value={preview.css} compact />
                </div>
              </div>
              <button
                type="button"
                className="primary-button"
                onClick={() => onAddColour(preview.css, "Composite")}
              >
                Add result to palette
              </button>
            </>
          )}
          <details>
            <summary>How the result is calculated</summary>
            <p>
              Porter–Duff source-over is applied from the bottom layer upward.
              Encoded sRGB matches common quick calculators; linear-light sRGB
              is physically closer for emitted light and often looks brighter.
              Blend modes are applied before alpha compositing.
            </p>
          </details>
        </aside>
      </div>
    </div>
  );
 }
@@ -0,0 +1,406 @@
 import { useMemo, useState } from "react";
 import {
  contrastReport,
  deltaE,
  gamutReport,
  nearestPassingColour,
  simulateColourVision,
  toSrgbPreview,
  tryParseColour,
  type ColourVisionDeficiency,
  type DeltaEMethod,
 } from "../colour";
 import { ColourField } from "./ColourField";
 import { CopyButton } from "./CopyButton";
 const DEFICIENCIES: Array<{ id: ColourVisionDeficiency; label: string }> = [
  { id: "protanopia", label: "Protanopia" },
  { id: "deuteranopia", label: "Deuteranopia" },
  { id: "tritanopia", label: "Tritanopia" },
  { id: "achromatopsia", label: "Achromatopsia" },
 ];
 export function ContrastLab({
  onAddColour,
 }: {
  onAddColour: (colour: string, name?: string) => void;
 }) {
  const [foreground, setForeground] = useState("#2d2859");
  const [background, setBackground] = useState("#f8f5ee");
  const [canvas, setCanvas] = useState("#ffffff");
  const [target, setTarget] = useState(4.5);
  const [method, setMethod] = useState<DeltaEMethod>("2000");
  const [severity, setSeverity] = useState(1);
  const analysis = useMemo(() => {
    if (
      ![foreground, background, canvas].every(
        (value) => tryParseColour(value).ok,
      )
    )
      return null;
    try {
      const report = contrastReport(foreground, background, { canvas });
      const suggestion = nearestPassingColour(foreground, background, target, {
        canvas,
      });
      return {
        report,
        suggestion,
        difference: deltaE(foreground, background, method),
        foregroundPreview: toSrgbPreview(report.flattenedForeground),
        backgroundPreview: toSrgbPreview(report.flattenedBackground),
        gamut: gamutReport(foreground),
        simulations: DEFICIENCIES.map((item) => ({
          ...item,
          foreground: toSrgbPreview(
            simulateColourVision(foreground, item.id, { severity }),
          ).css,
          background: toSrgbPreview(
            simulateColourVision(background, item.id, { severity }),
          ).css,
        })),
      };
    } catch {
      return null;
    }
  }, [background, canvas, foreground, method, severity, target]);
  return (
    <div className="lab-stack">
      <header className="lab-heading">
        <div>
          <p className="eyebrow">Readable, distinguishable, in gamut</p>
          <h2>Contrast &amp; compare</h2>
          <p>
            Flatten transparency over a real canvas, test WCAG 2.x ratios and
            compare perceptual distance. Simulations are useful approximations,
            not a diagnosis or substitute for user testing.
          </p>
        </div>
        <button
          type="button"
          onClick={() => {
            setForeground(background);
            setBackground(foreground);
          }}
        >
          ⇄ Swap colours
        </button>
      </header>
      <div className="contrast-layout">
        <section className="panel contrast-controls">
          <ColourField
            id="contrast-foreground"
            label="Foreground"
            value={foreground}
            onChange={setForeground}
          />
          <ColourField
            id="contrast-background"
            label="Background"
            value={background}
            onChange={setBackground}
          />
          <ColourField
            id="contrast-canvas"
            label="Canvas below transparency"
            value={canvas}
            onChange={setCanvas}
            description="Used only where foreground or background has alpha."
          />
          <label className="field">
            <span className="field-label">Suggested foreground target</span>
            <select
              value={target}
              onChange={(event) => setTarget(Number(event.target.value))}
            >
              <option value="3">3:1 · UI / large text</option>
              <option value="4.5">4.5:1 · AA normal text</option>
              <option value="7">7:1 · AAA normal text</option>
            </select>
          </label>
          {analysis?.suggestion && (
            <div className="suggestion-card">
              <span
                className="mini-swatch checkerboard"
                style={
                  { "--swatch": analysis.suggestion.css } as React.CSSProperties
                }
              />
              <div>
                <strong>Nearest passing foreground</strong>
                <code>{analysis.suggestion.hex}</code>
                <small>
                  {analysis.suggestion.ratio.toFixed(2)}:1 · ΔE OK{" "}
                  {analysis.suggestion.deltaEOK.toFixed(3)}
                </small>
              </div>
              <CopyButton
                value={analysis.suggestion.css}
                compact
                label="Copy suggestion"
              />
              <button
                type="button"
                onClick={() =>
                  setForeground(analysis.suggestion?.css ?? foreground)
                }
              >
                Use
              </button>
            </div>
          )}
          {analysis && !analysis.suggestion && (
            <p className="stale-notice" role="status">
              No foreground at the current alpha can reach this target. Increase
              its opacity or change the background.
            </p>
          )}
        </section>
        <section className="panel contrast-results">
          {analysis ? (
            <>
              <div
                className="contrast-sample"
                style={{
                  color: analysis.foregroundPreview.css,
                  background: analysis.backgroundPreview.css,
                }}
              >
                <strong>Aa</strong>
                <span>Colour should carry meaning beautifully—not alone.</span>
                <button
                  type="button"
                  style={{
                    color: analysis.foregroundPreview.css,
                    borderColor: analysis.foregroundPreview.css,
                  }}
                >
                  Example control
                </button>
              </div>
              <div className="ratio-heading">
                <div>
                  <strong>{analysis.report.ratio.toFixed(2)}</strong>
                  <span>: 1 contrast</span>
                </div>
                <span
                  className={`status-chip ${analysis.report.passes.aaNormal ? "pass" : "fail"}`}
                >
                  {analysis.report.passes.aaNormal
                    ? "AA normal passes"
                    : "AA normal fails"}
                </span>
              </div>
              <div className="pass-grid">
                <Pass
                  label="UI & graphics"
                  threshold="3:1"
                  pass={analysis.report.passes.nonText}
                />
                <Pass
                  label="AA large text"
                  threshold="3:1"
                  pass={analysis.report.passes.aaLarge}
                />
                <Pass
                  label="AA normal text"
                  threshold="4.5:1"
                  pass={analysis.report.passes.aaNormal}
                />
                <Pass
                  label="AAA large text"
                  threshold="4.5:1"
                  pass={analysis.report.passes.aaaLarge}
                />
                <Pass
                  label="AAA normal text"
                  threshold="7:1"
                  pass={analysis.report.passes.aaaNormal}
                />
              </div>
              <p className="field-help">
                WCAG 2.x defines large text as at least 18pt, or 14pt bold.
                Check states, focus, disabled controls and non-colour cues
                separately.
              </p>
            </>
          ) : (
            <p className="field-error">
              Enter three valid colours to run the checks.
            </p>
          )}
        </section>
      </div>
      {analysis && (
        <div className="comparison-grid">
          <section className="panel">
            <div className="section-heading">
              <div>
                <h3>Perceptual difference</h3>
                <p>Different formulas answer different historical needs.</p>
              </div>
              <label className="field compact-control">
                <span className="field-label">ΔE method</span>
                <select
                  value={method}
                  onChange={(event) =>
                    setMethod(event.target.value as DeltaEMethod)
                  }
                >
                  <option value="2000">CIEDE2000</option>
                  <option value="ok">OKLab ΔE</option>
                  <option value="76">CIE76</option>
                  <option value="cmc">CMC</option>
                  <option value="itp">ΔE ITP</option>
                  <option value="jz">ΔE Jz</option>
                </select>
              </label>
            </div>
            <div className="delta-result">
              <strong>{analysis.difference.toFixed(3)}</strong>
              <span>ΔE {method}</span>
            </div>
            <p className="field-help">
              There is no universal “just noticeable” number across formulas,
              media, surrounds and observers. Use this as a comparison, not a
              pass/fail guarantee.
            </p>
            <div className="gamut-summary">
              <h3>Foreground gamut</h3>
              <div className="status-chip-row">
                {analysis.gamut.spaces.map((space) => (
                  <span
                    key={space.space}
                    className={`status-chip ${space.inGamut ? "pass" : "warn"}`}
                  >
                    {space.label} {space.inGamut ? "✓" : "↘"}
                  </span>
                ))}
              </div>
            </div>
          </section>
          <section className="panel">
            <div className="section-heading">
              <div>
                <h3>Colour-vision preview</h3>
                <p>Full-severity matrix approximation in linear sRGB.</p>
              </div>
              <label className="field compact-control">
                <span className="field-label">
                  Severity · {Math.round(severity * 100)}%
                </span>
                <input
                  type="range"
                  min="0"
                  max="1"
                  step="0.05"
                  value={severity}
                  onChange={(event) => setSeverity(Number(event.target.value))}
                />
              </label>
            </div>
            <div className="simulation-grid">
              {analysis.simulations.map((simulation) => (
                <article key={simulation.id}>
                  <div style={{ background: simulation.background }}>
                    <span style={{ color: simulation.foreground }}>Aa</span>
                  </div>
                  <strong>{simulation.label}</strong>
                </article>
              ))}
            </div>
          </section>
        </div>
      )}
      {analysis && (
        <section className="panel quick-matrix">
          <div className="section-heading">
            <div>
              <h3>Quick contrast matrix</h3>
              <p>Current colours against each other, black and white.</p>
            </div>
          </div>
          <div className="matrix-table" role="table">
            {[foreground, background, "#000000", "#ffffff"].map((fg, row) => (
              <div role="row" key={`${fg}-${row}`}>
                {[foreground, background, "#000000", "#ffffff"].map(
                  (bg, column) => {
                    const valid = fg !== bg;
                    let ratio = 1;
                    if (valid) ratio = contrastReport(fg, bg, { canvas }).ratio;
                    return (
                      <div
                        role="cell"
                        key={`${bg}-${column}`}
                        style={{
                          color: toSrgbPreview(fg).css,
                          background: toSrgbPreview(bg).css,
                        }}
                      >
                        <strong>{ratio.toFixed(1)}</strong>
                        <small>
                          {valid
                            ? ratio >= 4.5
                              ? "AA"
                              : ratio >= 3
                                ? "Large"
                                : "Fail"
                            : "Same"}
                        </small>
                      </div>
                    );
                  },
                )}
              </div>
            ))}
          </div>
          <div className="button-row">
            <button
              type="button"
              onClick={() =>
                onAddColour(analysis.foregroundPreview.css, "Foreground")
              }
            >
              Add foreground
            </button>
            <button
              type="button"
              onClick={() =>
                onAddColour(analysis.backgroundPreview.css, "Background")
              }
            >
              Add background
            </button>
          </div>
        </section>
      )}
    </div>
  );
 }
 function Pass({
  label,
  threshold,
  pass,
 }: {
  label: string;
  threshold: string;
  pass: boolean;
 }) {
  return (
    <div className={pass ? "passes" : "fails"}>
      <span aria-hidden="true">{pass ? "✓" : "×"}</span>
      <div>
        <strong>{label}</strong>
        <small>{threshold}</small>
      </div>
    </div>
  );
 }
@@ -0,0 +1,327 @@
 import { useMemo, useState } from "react";
 import {
  conversionRows,
  gamutReport,
  toSrgbPreview,
  tryParseColour,
  type ColourFormat,
  type ColourValue,
 } from "../colour";
 import { ColourField } from "./ColourField";
 import { CopyButton } from "./CopyButton";
 const EXAMPLES = [
  "#f8f5ee",
  "rgb(21 96 189 / 72%)",
  "oklch(68% 0.18 264 / .9)",
  "color(display-p3 0.91 0.24 0.42)",
 ];
 const CONVERSION_FORMATS: readonly ColourFormat[] = [
  "hex",
  "hex8",
  "rgb",
  "rgba",
  "hsl",
  "hsv",
  "hwb",
  "cmyk",
  "lab",
  "lch",
  "oklab",
  "oklch",
  "p3",
  "rec2020",
  "a98rgb",
  "prophoto",
  "xyz-d50",
  "xyz-d65",
 ];
 export function ConverterLab({
  onAddColour,
 }: {
  onAddColour: (colour: string, name?: string) => void;
 }) {
  const [input, setInput] = useState("#f8f5ee");
  const [precision, setPrecision] = useState(4);
  const parsed = useMemo(() => tryParseColour(input), [input]);
  const [lastValid, setLastValid] = useState<ColourValue | null>(() =>
    parsed.ok ? parsed.value : null,
  );
  function updateInput(value: string) {
    setInput(value);
    const result = tryParseColour(value);
    if (result.ok) setLastValid(result.value);
  }
  const rows = useMemo(
    () =>
      lastValid
        ? conversionRows(lastValid, CONVERSION_FORMATS).map((row) => ({
            ...row,
          }))
        : [],
    [lastValid],
  );
  const preview = lastValid ? toSrgbPreview(lastValid) : null;
  const gamut = lastValid ? gamutReport(lastValid) : null;
  return (
    <div className="lab-stack">
      <header className="lab-heading">
        <div>
          <p className="eyebrow">One colour, many representations</p>
          <h2>Convert colours</h2>
          <p>
            Parse CSS colour syntax without discarding wide-gamut coordinates.
            The large preview is mapped only for this display.
          </p>
        </div>
        <label className="field compact-control">
          <span className="field-label">Precision</span>
          <select
            value={precision}
            onChange={(event) => setPrecision(Number(event.target.value))}
          >
            {[2, 3, 4, 5, 6].map((value) => (
              <option key={value} value={value}>
                {value} decimals
              </option>
            ))}
          </select>
        </label>
      </header>
      <div className="two-column-layout converter-layout">
        <section className="panel input-panel">
          <ColourField
            id="convert-source"
            label="Colour"
            value={input}
            onChange={updateInput}
            description="Hex, named colours, rgb(), hsl(), hwb(), lab(), lch(), oklab(), oklch() and color()."
          />
          <div className="example-row" aria-label="Example colours">
            {EXAMPLES.map((example) => (
              <button
                key={example}
                type="button"
                onClick={() => updateInput(example)}
              >
                {example}
              </button>
            ))}
          </div>
          {preview && (
            <div className="hero-preview checkerboard">
              <div style={{ background: preview.css }} />
              <span>
                {preview.wasMapped
                  ? "Mapped to sRGB for preview"
                  : "In sRGB gamut"}
              </span>
            </div>
          )}
          {preview && (
            <div className="button-row">
              <button
                type="button"
                className="primary-button"
                onClick={() => onAddColour(preview.css, preview.hex)}
              >
                Add to palette
              </button>
              <CopyButton value={preview.hex} label={`Copy ${preview.hex}`} />
            </div>
          )}
          {gamut && (
            <div className="gamut-summary">
              <h3>Gamut</h3>
              <div className="status-chip-row">
                {gamut.spaces.map((space) => (
                  <span
                    key={space.space}
                    className={`status-chip ${space.inGamut ? "pass" : "warn"}`}
                    title={
                      space.inGamut
                        ? `Inside ${space.label}`
                        : `Outside ${space.label}; mapped ΔE OK ${space.deltaEOK.toFixed(3)}`
                    }
                  >
                    {space.label} {space.inGamut ? "✓" : "↘"}
                  </span>
                ))}
              </div>
              <p className="field-help">
                ↘ means the source is outside that gamut. Values below remain
                unmodified; each mapped value is labelled and copyable.
              </p>
              {gamut.spaces.some((space) => !space.inGamut) && (
                <div className="mapped-gamut-list">
                  {gamut.spaces
                    .filter((space) => !space.inGamut)
                    .map((space) => (
                      <div key={space.space}>
                        <span>{space.label} mapped</span>
                        <code>{space.mappedCss}</code>
                        <CopyButton
                          value={space.mappedCss}
                          label={`Copy mapped ${space.label}`}
                          compact
                        />
                      </div>
                    ))}
                </div>
              )}
            </div>
          )}
        </section>
        <section className="panel conversion-panel">
          <div className="section-heading">
            <div>
              <h3>Representations</h3>
              <p>Copy-ready CSS and developer formats.</p>
            </div>
          </div>
          <div
            className="conversion-list"
            aria-live="polite"
            aria-busy={!parsed.ok}
          >
            {rows.map((row) => {
              const rendered = row.value.replace(/(-?\d+\.\d{2,})/g, (number) =>
                Number(number)
                  .toFixed(precision)
                  .replace(/0+$/, "")
                  .replace(/\.$/, ""),
              );
              return (
                <div className="conversion-row" key={row.id}>
                  <span>{row.label}</span>
                  <code>{rendered}</code>
                  <CopyButton
                    value={rendered}
                    label={`Copy ${row.label}`}
                    compact
                  />
                </div>
              );
            })}
          </div>
          {!parsed.ok && lastValid && (
            <p className="stale-notice" role="status">
              Keeping the last valid conversion while you finish editing.
            </p>
          )}
        </section>
      </div>
      <BatchConverter onAddColour={onAddColour} />
    </div>
  );
 }
 function BatchConverter({
  onAddColour,
 }: {
  onAddColour: (colour: string, name?: string) => void;
 }) {
  const [source, setSource] = useState(
    ["#264653", "rgb(42 157 143)", "oklch(78% 0.15 85)", "rebeccapurple"].join(
      "\n",
    ),
  );
  const results = useMemo(
    () =>
      source
        .split(/\r?\n/)
        .map((line, index) => ({ line: line.trim(), index }))
        .filter(({ line }) => line.length > 0)
        .map(({ line, index }) => ({
          line,
          index,
          result: tryParseColour(line),
        })),
    [source],
  );
  const valid = results.filter((item) => item.result.ok);
  const exportText = valid
    .map((item) => {
      if (!item.result.ok) return "";
      const preview = toSrgbPreview(item.result.value);
      return `${item.line}\t${preview.hex}\t${preview.css}`;
    })
    .join("\n");
  return (
    <section className="panel batch-panel">
      <div className="section-heading">
        <div>
          <p className="eyebrow">Batch</p>
          <h3>Convert a colour list</h3>
          <p>
            One CSS colour per line. Invalid lines are isolated, not discarded
            silently.
          </p>
        </div>
        <div className="button-row">
          <CopyButton value={exportText} label="Copy table" />
          <button
            type="button"
            disabled={valid.length === 0}
            onClick={() =>
              valid.forEach((item) => {
                if (item.result.ok) {
                  const preview = toSrgbPreview(item.result.value);
                  onAddColour(preview.css, preview.hex);
                }
              })
            }
          >
            Add valid to palette
          </button>
        </div>
      </div>
      <div className="batch-grid">
        <label className="field">
          <span className="field-label">Source colours</span>
          <textarea
            value={source}
            onChange={(event) => setSource(event.target.value)}
            rows={8}
          />
        </label>
        <div
          className="batch-results"
          aria-label={`${valid.length} valid colours`}
        >
          {results.map((item) => {
            const preview = item.result.ok
              ? toSrgbPreview(item.result.value)
              : null;
            return (
              <div className="batch-result" key={`${item.index}-${item.line}`}>
                <span
                  className="mini-swatch checkerboard"
                  style={
                    {
                      "--swatch": preview?.css ?? "transparent",
                    } as React.CSSProperties
                  }
                />
                <code>{item.line}</code>
                {preview ? <strong>{preview.hex}</strong> : <em>Invalid</em>}
              </div>
            );
          })}
        </div>
      </div>
    </section>
  );
 }
@@ -0,0 +1,51 @@
 import { useEffect, useState } from "react";
 export function CopyButton({
  value,
  label = "Copy",
  compact = false,
 }: {
  value: string;
  label?: string;
  compact?: boolean;
 }) {
  const [copied, setCopied] = useState(false);
  useEffect(() => {
    if (!copied) return;
    const timer = globalThis.setTimeout(() => setCopied(false), 1400);
    return () => globalThis.clearTimeout(timer);
  }, [copied]);
  async function copy() {
    try {
      await navigator.clipboard.writeText(value);
      setCopied(true);
    } catch {
      const textarea = document.createElement("textarea");
      textarea.value = value;
      textarea.style.position = "fixed";
      textarea.style.opacity = "0";
      document.body.append(textarea);
      textarea.select();
      document.execCommand("copy");
      textarea.remove();
      setCopied(true);
    }
  }
  return (
    <button
      type="button"
      className={compact ? "icon-button copy-button" : "copy-button"}
      onClick={() => void copy()}
      title={compact ? label : undefined}
    >
      <svg aria-hidden="true" viewBox="0 0 24 24">
        <path d="M8 8V5.8A1.8 1.8 0 0 1 9.8 4h8.4A1.8 1.8 0 0 1 20 5.8v8.4a1.8 1.8 0 0 1-1.8 1.8H16M5.8 8h8.4A1.8 1.8 0 0 1 16 9.8v8.4a1.8 1.8 0 0 1-1.8 1.8H5.8A1.8 1.8 0 0 1 4 18.2V9.8A1.8 1.8 0 0 1 5.8 8Z" />
      </svg>
      {!compact && <span>{copied ? "Copied" : label}</span>}
      {compact && <span className="sr-only">{copied ? "Copied" : label}</span>}
    </button>
  );
 }
@@ -0,0 +1,104 @@
 import { useEffect, useRef } from "react";
 interface HelpDialogProps {
  open: boolean;
  onClose: () => void;
 }
 export function HelpDialog({ open, onClose }: HelpDialogProps) {
  const dialogRef = useRef<HTMLDialogElement>(null);
  useEffect(() => {
    const dialog = dialogRef.current;
    if (!dialog) return;
    if (open && !dialog.open) dialog.showModal();
    if (!open && dialog.open) dialog.close();
  }, [open]);
  return (
    <dialog
      ref={dialogRef}
      className="colour-dialog"
      aria-labelledby="help-title"
      onClose={onClose}
      onCancel={(event) => {
        event.preventDefault();
        onClose();
      }}
      onClick={(event) => {
        if (event.target === event.currentTarget) onClose();
      }}
    >
      <article className="dialog-card">
        <header className="dialog-heading">
          <div>
            <p className="eyebrow">Local colour lab</p>
            <h2 id="help-title">Colour Tools help</h2>
          </div>
          <button type="button" className="icon-button" onClick={onClose}>
            <span aria-hidden="true">×</span>
            <span className="sr-only">Close help</span>
          </button>
        </header>
        <div className="help-grid">
          <section>
            <h3>Convert</h3>
            <p>
              Enter CSS colours in modern or legacy syntax. Inspect coordinates
              in sRGB, HSL, HWB, Lab, LCH, OKLab, OKLCH and wide-gamut spaces,
              then copy a deliberate mapped or unmapped representation.
            </p>
          </section>
          <section>
            <h3>Composite</h3>
            <p>
              Stack any number of translucent colours over a matte. Drag layers
              to reorder them, disable or duplicate them, and compare encoded
              sRGB with linear-light source-over compositing.
            </p>
          </section>
          <section>
            <h3>Steps</h3>
            <p>
              Interpolate two or more stops in perceptual, RGB, cylindrical or
              wide-gamut spaces. Control hue travel and alpha, then export
              swatches, CSS custom properties or JSON.
            </p>
          </section>
          <section>
            <h3>Pick &amp; Image</h3>
            <p>
              Use the large picker, the browser eyedropper when available, or a
              local image. Image bytes remain in memory and are never uploaded.
              Click a pixel or extract a deterministic palette.
            </p>
          </section>
          <section>
            <h3>Contrast</h3>
            <p>
              Check WCAG 2.x contrast, compare perceptual distance, inspect
              gamut, preview approximate colour-vision simulations and find a
              nearby passing foreground.
            </p>
          </section>
          <section>
            <h3>Palette</h3>
            <p>
              Build harmonies, tints, shades and tones. Keep a small
              browser-local palette and export tokens as CSS, SCSS or JSON.
            </p>
          </section>
          <section>
            <h3>Privacy &amp; precision</h3>
            <p>
              There is no server processing or telemetry. Out-of-gamut values
              are retained for inspection; clipping or gamut mapping is always
              labelled. Browser rendering can still vary by display and colour
              management.
            </p>
          </section>
        </div>
      </article>
    </dialog>
  );
 }
@@ -0,0 +1,669 @@
 import {
  useCallback,
  useEffect,
  useRef,
  useState,
  type ChangeEvent,
  type DragEvent,
  type KeyboardEvent,
  type MouseEvent,
 } from "react";
 import {
  DEFAULT_IMAGE_LIMITS,
  decodeLocalImage,
  extractPaletteSafely,
  getBoundedSampleRegion,
  mapClientPointToPixel,
  samplePixels,
  validateImageDimensions,
  validateImageFile,
  type ExtractedPaletteColour,
  type ImageLimits,
  type LoadedImageDetails,
  type PixelPoint,
  type PixelSample,
  type SamplingMethod,
 } from "../palette";
 const EXTRACTION_PIXEL_LIMIT = 160_000;
 export interface ImagePickerLabProps {
  readonly onAddColour?: (colour: string) => void;
  readonly onPaletteExtracted?: (
    palette: readonly ExtractedPaletteColour[],
  ) => void;
  readonly imageLimits?: ImageLimits;
 }
 const formatBytes = (bytes: number): string => {
  if (bytes < 1024) return `${bytes} B`;
  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KiB`;
  return `${(bytes / (1024 * 1024)).toFixed(1)} MiB`;
 };
 const makeExtractionBuffer = (source: HTMLCanvasElement): ImageData => {
  const scale = Math.min(
    1,
    Math.sqrt(EXTRACTION_PIXEL_LIMIT / (source.width * source.height)),
  );
  const width = Math.max(1, Math.round(source.width * scale));
  const height = Math.max(1, Math.round(source.height * scale));
  if (width === source.width && height === source.height) {
    const context = source.getContext("2d", { willReadFrequently: true });
    if (!context) throw new Error("Canvas access is unavailable.");
    return context.getImageData(0, 0, width, height);
  }
  const reduced = document.createElement("canvas");
  reduced.width = width;
  reduced.height = height;
  const context = reduced.getContext("2d", { willReadFrequently: true });
  if (!context) throw new Error("Canvas access is unavailable.");
  context.imageSmoothingEnabled = true;
  context.imageSmoothingQuality = "high";
  context.drawImage(source, 0, 0, width, height);
  return context.getImageData(0, 0, width, height);
 };
 const statusForImage = (details: LoadedImageDetails): string =>
  `${details.name} loaded: ${details.width.toLocaleString()} by ${details.height.toLocaleString()} pixels.`;
 const boundedInputNumber = (
  value: number,
  current: number,
  minimum: number,
  maximum: number,
 ): number =>
  Number.isFinite(value)
    ? Math.min(maximum, Math.max(minimum, Math.round(value)))
    : current;
 export function ImagePickerLab({
  onAddColour,
  onPaletteExtracted,
  imageLimits = DEFAULT_IMAGE_LIMITS,
 }: ImagePickerLabProps) {
  const inputRef = useRef<HTMLInputElement>(null);
  const canvasRef = useRef<HTMLCanvasElement>(null);
  const loadGenerationRef = useRef(0);
  const loadAbortRef = useRef<AbortController | null>(null);
  const extractionAbortRef = useRef<AbortController | null>(null);
  const [image, setImage] = useState<LoadedImageDetails | null>(null);
  const [status, setStatus] = useState("Choose a local image to begin.");
  const [error, setError] = useState<string | null>(null);
  const [isDragging, setIsDragging] = useState(false);
  const [isLoading, setIsLoading] = useState(false);
  const [isExtracting, setIsExtracting] = useState(false);
  const [radius, setRadius] = useState(0);
  const [method, setMethod] = useState<SamplingMethod>("average");
  const [point, setPoint] = useState<PixelPoint>({ x: 0, y: 0 });
  const [sample, setSample] = useState<PixelSample | null>(null);
  const [paletteCount, setPaletteCount] = useState(6);
  const [palette, setPalette] = useState<ExtractedPaletteColour[]>([]);
  const stopExtraction = useCallback(() => {
    extractionAbortRef.current?.abort();
    extractionAbortRef.current = null;
    setIsExtracting(false);
  }, []);
  const clearCanvas = useCallback(() => {
    const canvas = canvasRef.current;
    if (canvas) {
      canvas.width = 0;
      canvas.height = 0;
    }
  }, []);
  const clearImage = useCallback(() => {
    loadGenerationRef.current += 1;
    loadAbortRef.current?.abort();
    loadAbortRef.current = null;
    stopExtraction();
    clearCanvas();
    setImage(null);
    setIsLoading(false);
    setSample(null);
    setPalette([]);
    onPaletteExtracted?.([]);
    setError(null);
    setStatus("Image removed. Choose another local image when ready.");
    if (inputRef.current) inputRef.current.value = "";
  }, [clearCanvas, onPaletteExtracted, stopExtraction]);
  useEffect(
    () => () => {
      loadGenerationRef.current += 1;
      loadAbortRef.current?.abort();
      extractionAbortRef.current?.abort();
      const canvas = canvasRef.current;
      if (canvas) {
        canvas.width = 0;
        canvas.height = 0;
      }
    },
    [],
  );
  const loadFile = useCallback(
    async (file: File) => {
      const validation = validateImageFile(file, imageLimits);
      if (!validation.valid) {
        setError(validation.message ?? "This image cannot be loaded.");
        setStatus("Image not loaded.");
        return;
      }
      const generation = ++loadGenerationRef.current;
      loadAbortRef.current?.abort();
      const loadController = new AbortController();
      loadAbortRef.current = loadController;
      stopExtraction();
      setIsLoading(true);
      setError(null);
      setStatus(`Decoding ${file.name} locally…`);
      try {
        const decoded = await decodeLocalImage(file, loadController.signal);
        if (generation !== loadGenerationRef.current) {
          decoded.dispose();
          return;
        }
        const dimensions = validateImageDimensions(
          decoded.width,
          decoded.height,
          imageLimits,
        );
        if (!dimensions.valid) {
          decoded.dispose();
          setError(
            dimensions.message ?? "This image is too large to process safely.",
          );
          setStatus("Image not loaded.");
          return;
        }
        const canvas = canvasRef.current;
        const context = canvas?.getContext("2d", { willReadFrequently: true });
        if (!canvas || !context) {
          decoded.dispose();
          throw new Error("Canvas access is unavailable in this browser.");
        }
        canvas.width = decoded.width;
        canvas.height = decoded.height;
        context.clearRect(0, 0, canvas.width, canvas.height);
        context.drawImage(decoded.source, 0, 0);
        decoded.dispose();
        const details: LoadedImageDetails = {
          name: file.name,
          mimeType: file.type,
          bytes: file.size,
          width: canvas.width,
          height: canvas.height,
        };
        setImage(details);
        setPoint({ x: 0, y: 0 });
        setSample(null);
        setPalette([]);
        onPaletteExtracted?.([]);
        setStatus(statusForImage(details));
      } catch (caught) {
        if (generation !== loadGenerationRef.current) return;
        const message =
          caught instanceof Error
            ? caught.message
            : "The image could not be decoded.";
        setError(message);
        setStatus("Image not loaded.");
      } finally {
        if (loadAbortRef.current === loadController)
          loadAbortRef.current = null;
        if (generation === loadGenerationRef.current) setIsLoading(false);
      }
    },
    [imageLimits, onPaletteExtracted, stopExtraction],
  );
  const acceptFiles = useCallback(
    (files: FileList | null) => {
      if (!files || files.length === 0) return;
      if (files.length > 1) {
        setError("Choose one image at a time.");
        setStatus("Image not loaded.");
        return;
      }
      const file = files.item(0);
      if (file) void loadFile(file);
    },
    [loadFile],
  );
  const takeSample = useCallback(
    (nextPoint: PixelPoint) => {
      const canvas = canvasRef.current;
      if (!canvas || !image) return;
      const region = getBoundedSampleRegion(
        nextPoint.x,
        nextPoint.y,
        radius,
        canvas.width,
        canvas.height,
      );
      const context = canvas.getContext("2d", { willReadFrequently: true });
      if (!region || !context) return;
      try {
        const pixels = context.getImageData(
          region.left,
          region.top,
          region.width,
          region.height,
        );
        const result = samplePixels(
          pixels,
          region.centerX,
          region.centerY,
          radius,
          method,
        );
        if (!result) return;
        const positioned = {
          ...result,
          x: region.left + result.x,
          y: region.top + result.y,
        };
        setPoint({ x: positioned.x, y: positioned.y });
        setSample(positioned);
        setError(null);
        setStatus(
          `${positioned.hex} sampled at x ${positioned.x}, y ${positioned.y}.`,
        );
      } catch {
        setError("The browser could not read pixels from this image.");
        setStatus("Sampling failed.");
      }
    },
    [image, method, radius],
  );
  const handleCanvasClick = (event: MouseEvent<HTMLCanvasElement>): void => {
    const canvas = canvasRef.current;
    if (!canvas) return;
    const nextPoint = mapClientPointToPixel(
      event.clientX,
      event.clientY,
      canvas.getBoundingClientRect(),
      canvas.width,
      canvas.height,
    );
    if (nextPoint) takeSample(nextPoint);
  };
  const handleCanvasKeyDown = (
    event: KeyboardEvent<HTMLCanvasElement>,
  ): void => {
    if (!image) return;
    const movement: Record<string, PixelPoint> = {
      ArrowLeft: { x: -1, y: 0 },
      ArrowRight: { x: 1, y: 0 },
      ArrowUp: { x: 0, y: -1 },
      ArrowDown: { x: 0, y: 1 },
    };
    const delta = movement[event.key];
    if (delta) {
      event.preventDefault();
      takeSample({
        x: Math.min(image.width - 1, Math.max(0, point.x + delta.x)),
        y: Math.min(image.height - 1, Math.max(0, point.y + delta.y)),
      });
    } else if (event.key === "Enter" || event.key === " ") {
      event.preventDefault();
      takeSample(point);
    }
  };
  const extract = async (): Promise<void> => {
    const canvas = canvasRef.current;
    if (!canvas || !image || isExtracting) return;
    stopExtraction();
    const controller = new AbortController();
    extractionAbortRef.current = controller;
    setIsExtracting(true);
    setError(null);
    setStatus(`Extracting ${paletteCount} colours locally…`);
    try {
      const pixels = makeExtractionBuffer(canvas);
      const result = await extractPaletteSafely(
        { data: pixels.data, width: pixels.width, height: pixels.height },
        { count: paletteCount },
        controller.signal,
      );
      if (controller.signal.aborted) return;
      setPalette(result);
      onPaletteExtracted?.(result);
      setStatus(
        result.length === 0
          ? "No visible colours were found in the image."
          : `${result.length} palette colours extracted locally.`,
      );
    } catch (caught) {
      if (controller.signal.aborted) return;
      setError(
        caught instanceof Error ? caught.message : "Palette extraction failed.",
      );
      setStatus("Palette extraction failed.");
    } finally {
      if (extractionAbortRef.current === controller) {
        extractionAbortRef.current = null;
        setIsExtracting(false);
      }
    }
  };
  return (
    <section
      className="image-picker-lab"
      aria-labelledby="image-picker-heading"
      aria-busy={isLoading || isExtracting}
    >
      <header className="image-picker-lab__header">
        <div>
          <p className="eyebrow">Local image colour lab</p>
          <h2 id="image-picker-heading">Pick and extract colours</h2>
          <p>
            Sample exact pixels or build a perceptual palette. Image bytes never
            leave this browser tab.
          </p>
        </div>
        {image ? (
          <button
            type="button"
            className="button button--quiet"
            onClick={clearImage}
          >
            Remove image
          </button>
        ) : null}
      </header>
      <div
        className={`image-picker-lab__dropzone${isDragging ? " is-dragging" : ""}`}
        onDragEnter={(event) => {
          event.preventDefault();
          setIsDragging(true);
        }}
        onDragOver={(event) => {
          event.preventDefault();
          event.dataTransfer.dropEffect = "copy";
        }}
        onDragLeave={(event) => {
          const related = event.relatedTarget;
          if (
            !(related instanceof Node) ||
            !event.currentTarget.contains(related)
          )
            setIsDragging(false);
        }}
        onDrop={(event: DragEvent<HTMLDivElement>) => {
          event.preventDefault();
          setIsDragging(false);
          acceptFiles(event.dataTransfer.files);
        }}
      >
        <div>
          <strong>Drop one image here</strong>
          <span>
            PNG, JPEG, WebP, GIF, or AVIF · up to{" "}
            {Math.round(imageLimits.maxBytes / 1024 / 1024)} MiB
          </span>
        </div>
        <button
          type="button"
          className="button"
          disabled={isLoading}
          onClick={() => inputRef.current?.click()}
        >
          {isLoading
            ? "Loading…"
            : image
              ? "Choose another image"
              : "Choose image"}
        </button>
        <input
          ref={inputRef}
          className="visually-hidden"
          type="file"
          accept={imageLimits.acceptedMimeTypes.join(",")}
          onChange={(event: ChangeEvent<HTMLInputElement>) => {
            acceptFiles(event.currentTarget.files);
            event.currentTarget.value = "";
          }}
        />
      </div>
      <p
        className={`image-picker-lab__status${error ? " is-error" : ""}`}
        role="status"
        aria-live="polite"
      >
        {error ?? status}
      </p>
      <div className="image-picker-lab__workspace" hidden={!image}>
        <div className="image-picker-lab__picker">
          {image ? (
            <div className="image-picker-lab__image-meta">
              <strong>{image.name}</strong>
              <span>
                {image.width.toLocaleString()} × {image.height.toLocaleString()}{" "}
                px · {formatBytes(image.bytes)}
              </span>
            </div>
          ) : null}
          <div className="image-picker-lab__canvas-wrap">
            <canvas
              ref={canvasRef}
              className="image-picker-lab__canvas"
              onClick={handleCanvasClick}
              onKeyDown={handleCanvasKeyDown}
              tabIndex={0}
              role="img"
              aria-label={
                image
                  ? `Colour picker for ${image.name}. Click a pixel, use the arrow keys, or enter coordinates below.`
                  : "Local image colour picker"
              }
            >
              Colour picker image canvas.
            </canvas>
          </div>
        </div>
        {image ? (
          <aside
            className="image-picker-lab__controls"
            aria-label="Image colour controls"
          >
            <fieldset className="control-group">
              <legend>Pixel sampling</legend>
              <div className="field-grid field-grid--compact">
                <label>
                  X coordinate
                  <input
                    type="number"
                    min={0}
                    max={image.width - 1}
                    value={point.x}
                    onChange={(event) => {
                      const value = event.currentTarget.valueAsNumber;
                      setPoint((current) => ({
                        ...current,
                        x: boundedInputNumber(
                          value,
                          current.x,
                          0,
                          image.width - 1,
                        ),
                      }));
                    }}
                  />
                </label>
                <label>
                  Y coordinate
                  <input
                    type="number"
                    min={0}
                    max={image.height - 1}
                    value={point.y}
                    onChange={(event) => {
                      const value = event.currentTarget.valueAsNumber;
                      setPoint((current) => ({
                        ...current,
                        y: boundedInputNumber(
                          value,
                          current.y,
                          0,
                          image.height - 1,
                        ),
                      }));
                    }}
                  />
                </label>
                <label>
                  Radius
                  <input
                    type="number"
                    min={0}
                    max={24}
                    value={radius}
                    onChange={(event) =>
                      setRadius((current) =>
                        boundedInputNumber(
                          event.currentTarget.valueAsNumber,
                          current,
                          0,
                          24,
                        ),
                      )
                    }
                  />
                </label>
                <label>
                  Method
                  <select
                    value={method}
                    onChange={(event) =>
                      setMethod(event.currentTarget.value as SamplingMethod)
                    }
                  >
                    <option value="average">Alpha-weighted average</option>
                    <option value="median">Median</option>
                  </select>
                </label>
              </div>
              <button
                type="button"
                className="button button--wide"
                onClick={() =>
                  takeSample({
                    x: Math.min(
                      image.width - 1,
                      Math.max(0, Math.round(point.x)),
                    ),
                    y: Math.min(
                      image.height - 1,
                      Math.max(0, Math.round(point.y)),
                    ),
                  })
                }
              >
                Sample coordinate
              </button>
              {sample ? (
                <div
                  className="image-picker-lab__sample"
                  aria-label={`Sampled colour ${sample.hex}`}
                >
                  <span
                    className="colour-swatch colour-swatch--large"
                    style={{ backgroundColor: sample.css }}
                  />
                  <div>
                    <strong>{sample.hex}</strong>
                    <span>
                      x {sample.x}, y {sample.y} · {sample.pixelCount} pixel
                      {sample.pixelCount === 1 ? "" : "s"}
                    </span>
                  </div>
                  {onAddColour ? (
                    <button
                      type="button"
                      className="button button--quiet"
                      onClick={() => onAddColour(sample.hex)}
                    >
                      Add colour
                    </button>
                  ) : null}
                </div>
              ) : null}
            </fieldset>
            <fieldset className="control-group">
              <legend>Perceptual palette</legend>
              <label>
                Number of colours
                <input
                  type="range"
                  min={2}
                  max={12}
                  value={paletteCount}
                  onChange={(event) =>
                    setPaletteCount(Number(event.currentTarget.value))
                  }
                />
                <output>{paletteCount}</output>
              </label>
              <button
                type="button"
                className="button button--wide"
                disabled={isExtracting}
                onClick={() => void extract()}
              >
                {isExtracting ? "Extracting…" : "Extract palette"}
              </button>
              {palette.length > 0 ? (
                <ul
                  className="image-picker-lab__palette"
                  aria-label="Extracted image palette"
                >
                  {palette.map((colour, index) => (
                    <li key={`${colour.hex}-${index}`}>
                      <button
                        type="button"
                        title={onAddColour ? `Add ${colour.hex}` : colour.hex}
                        onClick={() => onAddColour?.(colour.hex)}
                        disabled={!onAddColour}
                      >
                        <span
                          className="colour-swatch"
                          style={{ backgroundColor: colour.css }}
                        />
                        <strong>{colour.hex}</strong>
                        <span>
                          {colour.coverage > 0 && colour.coverage < 0.01
                            ? "<1%"
                            : `${Math.round(colour.coverage * 100)}%`}
                        </span>
                      </button>
                    </li>
                  ))}
                </ul>
              ) : null}
            </fieldset>
          </aside>
        ) : null}
      </div>
    </section>
  );
 }
 export default ImagePickerLab;
@@ -0,0 +1,418 @@
 import { useMemo, useState } from "react";
 import {
  colourHarmony,
  exportPalette,
  parsePaletteList,
  shades,
  tints,
  tones,
  toSrgbPreview,
  tryParseColour,
  type HarmonyType,
  type PaletteEntry,
  type PaletteExportFormat,
 } from "../colour";
 import type { useSavedPalette } from "../hooks/useSavedPalette";
 import { ColourField } from "./ColourField";
 import { CopyButton } from "./CopyButton";
 type PaletteStore = ReturnType<typeof useSavedPalette>;
 type GeneratorMode = HarmonyType | "tints" | "shades" | "tones";
 const MODES: Array<{ id: GeneratorMode; label: string }> = [
  { id: "complementary", label: "Complementary" },
  { id: "analogous", label: "Analogous" },
  { id: "split-complementary", label: "Split complement" },
  { id: "triadic", label: "Triadic" },
  { id: "tetradic", label: "Tetradic" },
  { id: "square", label: "Square" },
  { id: "tints", label: "Tints" },
  { id: "shades", label: "Shades" },
  { id: "tones", label: "Tones" },
 ];
 export function PaletteLab({ palette }: { palette: PaletteStore }) {
  const [base, setBase] = useState("oklch(64% 0.18 276)");
  const [mode, setMode] = useState<GeneratorMode>("analogous");
  const [count, setCount] = useState(6);
  const [format, setFormat] = useState<PaletteExportFormat>("css");
  const [prefix, setPrefix] = useState("brand");
  const [importText, setImportText] = useState("");
  const [importMessage, setImportMessage] = useState("");
  const generated = useMemo(() => {
    const parsed = tryParseColour(base);
    if (!parsed.ok) return [];
    if (mode === "tints")
      return tints(parsed.value, count - 1, {
        includeBase: true,
        includeEndpoint: true,
      });
    if (mode === "shades")
      return shades(parsed.value, count - 1, {
        includeBase: true,
        includeEndpoint: true,
      });
    if (mode === "tones")
      return tones(parsed.value, count - 1, {
        includeBase: true,
        includeEndpoint: true,
      });
    return colourHarmony(parsed.value, mode);
  }, [base, count, mode]);
  const entries = useMemo<PaletteEntry[]>(
    () =>
      palette.colours.flatMap((entry) => {
        const result = tryParseColour(entry.value);
        return result.ok
          ? [{ name: entry.name, colour: result.value, source: entry.value }]
          : [];
      }),
    [palette.colours],
  );
  const exported =
    entries.length > 0
      ? exportPalette(entries, format, { prefix, pretty: true })
      : "";
  function importPalette() {
    try {
      const imported = parsePaletteList(importText);
      imported.forEach((entry) => {
        const preview = toSrgbPreview(entry.colour);
        palette.addColour(preview.css, entry.name);
      });
      setImportMessage(
        `Added ${imported.length} colour${imported.length === 1 ? "" : "s"}.`,
      );
    } catch (error) {
      setImportMessage(
        error instanceof Error
          ? error.message
          : "Could not parse this palette.",
      );
    }
  }
  function download() {
    if (!exported) return;
    const extension =
      format === "scss"
        ? "scss"
        : format === "css"
          ? "css"
          : format === "csv"
            ? "csv"
            : format === "tailwind"
              ? "js"
              : "json";
    const blob = new Blob([exported], { type: "text/plain;charset=utf-8" });
    const url = URL.createObjectURL(blob);
    const anchor = document.createElement("a");
    anchor.href = url;
    anchor.download = `colour-palette.${extension}`;
    anchor.click();
    URL.revokeObjectURL(url);
  }
  function moveSavedColour(index: number, direction: -1 | 1) {
    const target = index + direction;
    if (target < 0 || target >= palette.colours.length) return;
    const current = palette.colours[index];
    const other = palette.colours[target];
    if (!current || !other) return;
    const copy = [...palette.colours];
    copy[index] = other;
    copy[target] = current;
    palette.replaceColours(copy);
  }
  return (
    <div className="lab-stack">
      <header className="lab-heading">
        <div>
          <p className="eyebrow">From one colour to a working system</p>
          <h2>Build a palette</h2>
          <p>
            Generate perceptual relationships, curate local swatches and export
            predictable developer tokens. Nothing leaves browser storage.
          </p>
        </div>
        <span className="count-badge">{palette.colours.length} saved</span>
      </header>
      <div className="palette-generator-layout">
        <section className="panel generator-controls">
          <ColourField
            id="palette-base"
            label="Base colour"
            value={base}
            onChange={setBase}
          />
          <label className="field">
            <span className="field-label">Relationship</span>
            <select
              value={mode}
              onChange={(event) => setMode(event.target.value as GeneratorMode)}
            >
              {MODES.map((item) => (
                <option key={item.id} value={item.id}>
                  {item.label}
                </option>
              ))}
            </select>
          </label>
          {["tints", "shades", "tones"].includes(mode) && (
            <label className="field">
              <span className="field-label">Scale size · {count}</span>
              <input
                type="range"
                min="3"
                max="12"
                value={count}
                onChange={(event) => setCount(Number(event.target.value))}
              />
            </label>
          )}
          <button
            type="button"
            className="primary-button"
            disabled={generated.length === 0}
            onClick={() =>
              generated.forEach((colour, index) => {
                const preview = toSrgbPreview(colour);
                palette.addColour(
                  preview.css,
                  `${MODES.find((item) => item.id === mode)?.label ?? mode} ${index + 1}`,
                );
              })
            }
          >
            Add generated palette
          </button>
        </section>
        <section className="panel generated-palette">
          <div className="section-heading">
            <div>
              <h3>Generated colours</h3>
              <p>Mapped to sRGB only for browser-safe swatches.</p>
            </div>
          </div>
          <div className="generated-swatches">
            {generated.map((colour, index) => {
              const preview = toSrgbPreview(colour);
              return (
                <button
                  key={`${preview.hex}-${index}`}
                  type="button"
                  style={{ "--swatch": preview.css } as React.CSSProperties}
                  className="checkerboard"
                  onClick={() =>
                    palette.addColour(preview.css, `${mode} ${index + 1}`)
                  }
                >
                  <span>{index + 1}</span>
                  <code>{preview.hex}</code>
                </button>
              );
            })}
          </div>
        </section>
      </div>
      <section className="panel saved-palette">
        <div className="section-heading">
          <div>
            <p className="eyebrow">Browser-local</p>
            <h3>Saved palette</h3>
            <p>Names and colours persist on this device until cleared.</p>
          </div>
          <div className="button-row">
            <button
              type="button"
              onClick={() =>
                palette.addColour(
                  "#7b61ff",
                  `Colour ${palette.colours.length + 1}`,
                )
              }
            >
              + Add colour
            </button>
            <button
              type="button"
              className="danger"
              disabled={palette.colours.length === 0}
              onClick={() => {
                if (confirm("Clear the saved palette on this device?"))
                  palette.clearColours();
              }}
            >
              Clear
            </button>
          </div>
        </div>
        {palette.colours.length === 0 ? (
          <div className="empty-state">
            <strong>No saved colours yet</strong>
            <p>
              Add a conversion, composite, step, picked pixel or generated
              harmony.
            </p>
          </div>
        ) : (
          <ol className="saved-colour-list">
            {palette.colours.map((entry, index) => {
              const result = tryParseColour(entry.value);
              const preview = result.ok ? toSrgbPreview(result.value) : null;
              return (
                <li key={entry.id}>
                  <span
                    className="palette-swatch checkerboard"
                    style={
                      {
                        "--swatch": preview?.css ?? "transparent",
                      } as React.CSSProperties
                    }
                  />
                  <label className="field">
                    <span className="field-label">Token name</span>
                    <input
                      value={entry.name}
                      onChange={(event) =>
                        palette.updateColour(entry.id, {
                          name: event.target.value,
                        })
                      }
                    />
                  </label>
                  <ColourField
                    id={`${entry.id}-saved-colour`}
                    label="Value"
                    value={entry.value}
                    onChange={(value) =>
                      palette.updateColour(entry.id, { value })
                    }
                    compact
                  />
                  <div className="layer-actions">
                    <button
                      type="button"
                      className="icon-button"
                      disabled={index === 0}
                      onClick={() => moveSavedColour(index, -1)}
                      title="Move up"
                    >
                      ↑
                    </button>
                    <button
                      type="button"
                      className="icon-button"
                      disabled={index === palette.colours.length - 1}
                      onClick={() => moveSavedColour(index, 1)}
                      title="Move down"
                    >
                      ↓
                    </button>
                    <button
                      type="button"
                      className="icon-button danger"
                      onClick={() => palette.removeColour(entry.id)}
                      title="Remove"
                    >
                      ×
                    </button>
                  </div>
                </li>
              );
            })}
          </ol>
        )}
      </section>
      <div className="palette-io-layout">
        <section className="panel">
          <div className="section-heading">
            <div>
              <h3>Import palette text</h3>
              <p>
                JSON, one colour per line, or <code>name: colour</code>.
              </p>
            </div>
          </div>
          <label className="field">
            <span className="field-label">Palette data</span>
            <textarea
              rows={8}
              value={importText}
              onChange={(event) => {
                setImportText(event.target.value);
                setImportMessage("");
              }}
              placeholder={"primary: #6252d3\naccent: oklch(76% 0.17 87)"}
            />
          </label>
          <div className="button-row">
            <button
              type="button"
              disabled={!importText.trim()}
              onClick={importPalette}
            >
              Import colours
            </button>
            {importMessage && (
              <span className="field-help" role="status">
                {importMessage}
              </span>
            )}
          </div>
        </section>
        <section className="panel">
          <div className="section-heading">
            <div>
              <h3>Export tokens</h3>
              <p>Duplicate names are made deterministic.</p>
            </div>
            <div className="button-row">
              <CopyButton value={exported} label="Copy" />
              <button type="button" disabled={!exported} onClick={download}>
                Download
              </button>
            </div>
          </div>
          <div className="export-controls">
            <label className="field">
              <span className="field-label">Format</span>
              <select
                value={format}
                onChange={(event) =>
                  setFormat(event.target.value as PaletteExportFormat)
                }
              >
                <option value="css">CSS custom properties</option>
                <option value="scss">SCSS variables</option>
                <option value="json">JSON</option>
                <option value="tokens">Design Tokens JSON</option>
                <option value="tailwind">JavaScript object</option>
                <option value="csv">CSV</option>
              </select>
            </label>
            <label className="field">
              <span className="field-label">Prefix</span>
              <input
                value={prefix}
                onChange={(event) => setPrefix(event.target.value)}
              />
            </label>
          </div>
          <pre className="export-preview">
            <code>
              {exported || "Add valid saved colours to export tokens."}
            </code>
          </pre>
        </section>
      </div>
    </div>
  );
 }
@@ -0,0 +1,387 @@
 import {
  useMemo,
  useRef,
  useState,
  type PointerEvent as ReactPointerEvent,
 } from "react";
 import { conversionRows, toSrgbPreview, tryParseColour } from "../colour";
 import { ColourField } from "./ColourField";
 import { CopyButton } from "./CopyButton";
 interface EyeDropperResult {
  sRGBHex: string;
 }
 interface EyeDropperConstructor {
  new (): { open: () => Promise<EyeDropperResult> };
 }
 declare global {
  interface Window {
    EyeDropper?: EyeDropperConstructor;
  }
 }
 function clamp(value: number, min = 0, max = 1) {
  return Math.min(max, Math.max(min, value));
 }
 function hsvToRgb(hue: number, saturation: number, value: number) {
  const chroma = value * saturation;
  const section = (((hue % 360) + 360) % 360) / 60;
  const x = chroma * (1 - Math.abs((section % 2) - 1));
  const [r1, g1, b1] =
    section < 1
      ? [chroma, x, 0]
      : section < 2
        ? [x, chroma, 0]
        : section < 3
          ? [0, chroma, x]
          : section < 4
            ? [0, x, chroma]
            : section < 5
              ? [x, 0, chroma]
              : [chroma, 0, x];
  const m = value - chroma;
  return [r1 + m, g1 + m, b1 + m] as const;
 }
 function rgbToHsv(r: number, g: number, b: number) {
  const max = Math.max(r, g, b);
  const min = Math.min(r, g, b);
  const delta = max - min;
  let hue = 0;
  if (delta > 0) {
    if (max === r) hue = 60 * (((g - b) / delta) % 6);
    else if (max === g) hue = 60 * ((b - r) / delta + 2);
    else hue = 60 * ((r - g) / delta + 4);
  }
  return {
    hue: hue < 0 ? hue + 360 : hue,
    saturation: max === 0 ? 0 : delta / max,
    value: max,
  };
 }
 function pickerCss(
  hue: number,
  saturation: number,
  brightness: number,
  alpha: number,
 ) {
  const [r, g, b] = hsvToRgb(hue, saturation, brightness);
  return `rgb(${Math.round(r * 255)} ${Math.round(g * 255)} ${Math.round(b * 255)} / ${Math.round(alpha * 1000) / 1000})`;
 }
 export function PickerLab({
  onAddColour,
 }: {
  onAddColour: (colour: string, name?: string) => void;
 }) {
  const [hue, setHue] = useState(264);
  const [saturation, setSaturation] = useState(0.62);
  const [brightness, setBrightness] = useState(0.82);
  const [alpha, setAlpha] = useState(1);
  const [text, setText] = useState("#834fd1");
  const [recent, setRecent] = useState<string[]>([]);
  const planeRef = useRef<HTMLDivElement>(null);
  const colour = useMemo(
    () => pickerCss(hue, saturation, brightness, alpha),
    [alpha, brightness, hue, saturation],
  );
  const parsed = tryParseColour(colour);
  const preview = parsed.ok ? toSrgbPreview(parsed.value) : null;
  const rows = parsed.ok ? conversionRows(parsed.value) : [];
  function remember(value: string) {
    setRecent((current) =>
      [value, ...current.filter((item) => item !== value)].slice(0, 12),
    );
  }
  function applyColour(value: string) {
    setText(value);
    const result = tryParseColour(value);
    if (!result.ok) return;
    const srgb = toSrgbPreview(result.value);
    const hsv = rgbToHsv(...srgb.rgb);
    setHue(hsv.hue);
    setSaturation(hsv.saturation);
    setBrightness(hsv.value);
    setAlpha(srgb.alpha);
    remember(srgb.hex);
  }
  function updateVisual(
    update: Partial<{
      hue: number;
      saturation: number;
      brightness: number;
      alpha: number;
    }>,
  ) {
    const nextHue = update.hue ?? hue;
    const nextSaturation = update.saturation ?? saturation;
    const nextBrightness = update.brightness ?? brightness;
    const nextAlpha = update.alpha ?? alpha;
    setHue(nextHue);
    setSaturation(nextSaturation);
    setBrightness(nextBrightness);
    setAlpha(nextAlpha);
    const next = tryParseColour(
      pickerCss(nextHue, nextSaturation, nextBrightness, nextAlpha),
    );
    if (next.ok) setText(toSrgbPreview(next.value).hex);
  }
  function selectFromPlane(event: ReactPointerEvent<HTMLDivElement>) {
    const plane = planeRef.current;
    if (!plane) return;
    if (event.type === "pointerdown") plane.setPointerCapture(event.pointerId);
    const bounds = plane.getBoundingClientRect();
    updateVisual({
      saturation: clamp((event.clientX - bounds.left) / bounds.width),
      brightness: 1 - clamp((event.clientY - bounds.top) / bounds.height),
    });
  }
  async function openEyeDropper() {
    if (!window.EyeDropper) return;
    try {
      const result = await new window.EyeDropper().open();
      applyColour(result.sRGBHex);
    } catch {
      // Escape and browser cancellation are normal outcomes.
    }
  }
  function nudge(event: React.KeyboardEvent<HTMLDivElement>) {
    const step = event.shiftKey ? 0.05 : 0.01;
    if (
      !["ArrowLeft", "ArrowRight", "ArrowUp", "ArrowDown"].includes(event.key)
    )
      return;
    event.preventDefault();
    if (event.key === "ArrowLeft")
      updateVisual({ saturation: clamp(saturation - step) });
    if (event.key === "ArrowRight")
      updateVisual({ saturation: clamp(saturation + step) });
    if (event.key === "ArrowDown")
      updateVisual({ brightness: clamp(brightness - step) });
    if (event.key === "ArrowUp")
      updateVisual({ brightness: clamp(brightness + step) });
  }
  return (
    <div className="lab-stack">
      <header className="lab-heading">
        <div>
          <p className="eyebrow">A picker with room to breathe</p>
          <h2>Pick a colour</h2>
          <p>
            Drag across the large saturation/value field, enter an exact CSS
            colour, or sample any visible pixel with a supported browser.
          </p>
        </div>
        <div className="button-row">
          {window.EyeDropper && (
            <button type="button" onClick={() => void openEyeDropper()}>
              ⌖ Pick from screen
            </button>
          )}
          <label className="native-colour-button">
            <input
              type="color"
              value={preview?.hex.slice(0, 7) ?? "#7656d6"}
              onChange={(event) => applyColour(event.target.value)}
            />
            Native picker
          </label>
        </div>
      </header>
      <div className="picker-layout">
        <section className="panel picker-panel">
          <div
            ref={planeRef}
            className="picker-plane"
            style={
              { "--picker-hue": `hsl(${hue} 100% 50%)` } as React.CSSProperties
            }
            onPointerDown={selectFromPlane}
            onPointerMove={(event) => {
              if (event.buttons === 1) selectFromPlane(event);
            }}
            onKeyDown={nudge}
            tabIndex={0}
            role="application"
            aria-label={`Saturation ${Math.round(saturation * 100)} percent, brightness ${Math.round(brightness * 100)} percent. Use arrow keys to adjust.`}
          >
            <span
              className="picker-cursor"
              style={{
                left: `${saturation * 100}%`,
                top: `${(1 - brightness) * 100}%`,
                background: colour,
              }}
            />
          </div>
          <label className="field hue-slider">
            <span className="field-label">Hue · {Math.round(hue)}°</span>
            <input
              type="range"
              min="0"
              max="360"
              step="1"
              value={hue}
              onChange={(event) =>
                updateVisual({ hue: Number(event.target.value) })
              }
            />
          </label>
          <label className="field alpha-slider">
            <span className="field-label">
              Alpha · {Math.round(alpha * 100)}%
            </span>
            <span
              className="alpha-track checkerboard"
              style={
                {
                  "--opaque": `rgb(${hsvToRgb(hue, saturation, brightness)
                    .map((channel) => Math.round(channel * 255))
                    .join(" ")})`,
                } as React.CSSProperties
              }
            >
              <input
                type="range"
                min="0"
                max="1"
                step="0.01"
                value={alpha}
                onChange={(event) =>
                  updateVisual({ alpha: Number(event.target.value) })
                }
              />
            </span>
          </label>
          <div className="picker-numbers">
            <label className="field">
              <span className="field-label">H</span>
              <input
                type="number"
                min="0"
                max="360"
                value={Math.round(hue)}
                onChange={(event) =>
                  updateVisual({
                    hue: clamp(Number(event.target.value), 0, 360),
                  })
                }
              />
            </label>
            <label className="field">
              <span className="field-label">S %</span>
              <input
                type="number"
                min="0"
                max="100"
                value={Math.round(saturation * 100)}
                onChange={(event) =>
                  updateVisual({
                    saturation: clamp(Number(event.target.value) / 100),
                  })
                }
              />
            </label>
            <label className="field">
              <span className="field-label">V %</span>
              <input
                type="number"
                min="0"
                max="100"
                value={Math.round(brightness * 100)}
                onChange={(event) =>
                  updateVisual({
                    brightness: clamp(Number(event.target.value) / 100),
                  })
                }
              />
            </label>
            <label className="field">
              <span className="field-label">A %</span>
              <input
                type="number"
                min="0"
                max="100"
                value={Math.round(alpha * 100)}
                onChange={(event) =>
                  updateVisual({
                    alpha: clamp(Number(event.target.value) / 100),
                  })
                }
              />
            </label>
          </div>
        </section>
        <aside className="panel picker-output">
          <div className="picked-preview checkerboard">
            <div style={{ background: colour }} />
          </div>
          <ColourField
            id="picker-exact"
            label="Exact CSS colour"
            value={text}
            onChange={applyColour}
            description="Entering a valid colour updates the visual picker."
          />
          <div className="result-values compact-values">
            {rows.slice(0, 8).map((row) => (
              <div key={row.id}>
                <span>{row.label}</span>
                <code>{row.value}</code>
                <CopyButton
                  value={row.copyValue}
                  label={`Copy ${row.label}`}
                  compact
                />
              </div>
            ))}
          </div>
          <button
            type="button"
            className="primary-button"
            onClick={() => {
              if (!preview) return;
              remember(preview.hex);
              onAddColour(preview.css, preview.hex);
            }}
          >
            Add to palette
          </button>
          {recent.length > 0 && (
            <div className="recent-colours">
              <h3>Recent picks</h3>
              <div>
                {recent.map((value) => (
                  <button
                    key={value}
                    type="button"
                    className="checkerboard"
                    style={{ "--swatch": value } as React.CSSProperties}
                    onClick={() => applyColour(value)}
                    title={value}
                  >
                    <span className="sr-only">Select {value}</span>
                  </button>
                ))}
              </div>
            </div>
          )}
        </aside>
      </div>
    </div>
  );
 }
@@ -0,0 +1,375 @@
 import { useMemo, useState } from "react";
 import {
  interpolateStops,
  tryParseColour,
  type ColourStop,
  type EasingName,
  type HueInterpolation,
  type InterpolationSpace,
  type InterpolationStep,
 } from "../colour";
 import { ColourField } from "./ColourField";
 import { CopyButton } from "./CopyButton";
 interface StopState {
  id: string;
  colour: string;
  position: string;
 }
 interface StepsConfig {
  stops: StopState[];
  count: number;
  space: InterpolationSpace;
  hue: HueInterpolation;
  easing: EasingName;
  premultiplied: boolean;
 }
 function calculateSteps(config: StepsConfig): {
  steps: InterpolationStep[] | null;
  error: string | null;
 } {
  if (config.stops.some((stop) => !tryParseColour(stop.colour).ok)) {
    return {
      steps: null,
      error: "Finish editing invalid stops to recalculate.",
    };
  }
  let previousPosition = -Infinity;
  for (const stop of config.stops) {
    if (!stop.position.trim()) continue;
    const position = Number(stop.position);
    if (!Number.isFinite(position) || position < 0 || position > 100) {
      return {
        steps: null,
        error: "Stop positions must be numbers from 0 to 100 percent.",
      };
    }
    if (position < previousPosition) {
      return {
        steps: null,
        error: "Stop positions must stay in ascending order.",
      };
    }
    previousPosition = position;
  }
  const colourStops: ColourStop[] = config.stops.map((stop, index) => {
    const numeric = Number(stop.position);
    return {
      colour: stop.colour,
      name: `Stop ${index + 1}`,
      position:
        stop.position.trim() && Number.isFinite(numeric)
          ? Math.min(1, Math.max(0, numeric / 100))
          : undefined,
    };
  });
  try {
    return {
      steps: interpolateStops(colourStops, config.count, {
        space: config.space,
        hue: config.hue,
        easing: config.easing,
        premultiplied: config.premultiplied,
      }),
      error: null,
    };
  } catch (error) {
    return {
      steps: null,
      error:
        error instanceof Error
          ? error.message
          : "Could not interpolate these stops.",
    };
  }
 }
 let stopSequence = 4;
 export function StepsLab({
  onAddColour,
 }: {
  onAddColour: (colour: string, name?: string) => void;
 }) {
  const initialConfig: StepsConfig = {
    stops: [
      { id: "stop-1", colour: "#ef476f", position: "0" },
      { id: "stop-2", colour: "oklch(82% 0.16 92)", position: "50" },
      { id: "stop-3", colour: "#118ab2", position: "100" },
    ],
    count: 9,
    space: "oklch",
    hue: "shorter",
    easing: "linear",
    premultiplied: true,
  };
  const [config, setConfig] = useState<StepsConfig>(initialConfig);
  const [lastGood, setLastGood] = useState<InterpolationStep[]>(
    () => calculateSteps(initialConfig).steps ?? [],
  );
  const { stops, count, space, hue, easing, premultiplied } = config;
  const calculation = useMemo(() => {
    return calculateSteps(config);
  }, [config]);
  const shownSteps = calculation.steps ?? lastGood;
  const cssVariables = shownSteps
    .map(
      (step, index) =>
        `  --colour-${String(index + 1).padStart(2, "0")}: ${step.css};`,
    )
    .join("\n");
  const cssExport = `:root {\n${cssVariables}\n}`;
  const jsonExport = JSON.stringify(
    shownSteps.map((step, index) => ({
      name: `colour-${index + 1}`,
      value: step.css,
      position: step.position,
    })),
    null,
    2,
  );
  const gradient = `linear-gradient(90deg, ${shownSteps
    .map((step) => `${step.css} ${(step.position * 100).toFixed(2)}%`)
    .join(", ")})`;
  function updateStop(id: string, update: Partial<StopState>) {
    commit({
      stops: stops.map((stop) =>
        stop.id === id ? { ...stop, ...update } : stop,
      ),
    });
  }
  function commit(update: Partial<StepsConfig>) {
    const next = { ...config, ...update };
    setConfig(next);
    const nextCalculation = calculateSteps(next);
    if (nextCalculation.steps) setLastGood(nextCalculation.steps);
  }
  return (
    <div className="lab-stack">
      <header className="lab-heading">
        <div>
          <p className="eyebrow">Perceptual ramps and exact endpoints</p>
          <h2>Step between colours</h2>
          <p>
            Use two or more stops. OKLCH keeps perceived lightness and
            colourfulness steadier; RGB modes help reproduce legacy output.
          </p>
        </div>
      </header>
      <div className="steps-layout">
        <section className="panel stop-editor">
          <div className="section-heading">
            <div>
              <h3>Stops</h3>
              <p>Positions are percentages along the ramp.</p>
            </div>
            <button
              type="button"
              onClick={() =>
                commit({
                  stops: [
                    ...stops,
                    {
                      id: `stop-${stopSequence++}`,
                      colour: "#7b61ff",
                      position: "",
                    },
                  ],
                })
              }
            >
              + Add stop
            </button>
          </div>
          <ol className="stop-list">
            {stops.map((stop, index) => (
              <li key={stop.id} className="stop-row">
                <span className="stop-index">{index + 1}</span>
                <ColourField
                  id={`${stop.id}-value`}
                  label="Colour"
                  value={stop.colour}
                  onChange={(colour) => updateStop(stop.id, { colour })}
                  compact
                />
                <label className="field position-field">
                  <span className="field-label">Position</span>
                  <span className="suffix-input">
                    <input
                      type="number"
                      min="0"
                      max="100"
                      step="0.1"
                      value={stop.position}
                      placeholder="auto"
                      onChange={(event) =>
                        updateStop(stop.id, { position: event.target.value })
                      }
                    />
                    <span>%</span>
                  </span>
                </label>
                <button
                  type="button"
                  className="icon-button danger"
                  disabled={stops.length <= 2}
                  onClick={() =>
                    commit({
                      stops: stops.filter((item) => item.id !== stop.id),
                    })
                  }
                  title="Remove stop"
                >
                  ×
                </button>
              </li>
            ))}
          </ol>
          <div className="control-grid">
            <label className="field">
              <span className="field-label">Swatches · {count}</span>
              <input
                type="range"
                min="2"
                max="32"
                value={count}
                onChange={(event) =>
                  commit({ count: Number(event.target.value) })
                }
              />
            </label>
            <label className="field">
              <span className="field-label">Interpolation space</span>
              <select
                value={space}
                onChange={(event) =>
                  commit({ space: event.target.value as InterpolationSpace })
                }
              >
                <optgroup label="Perceptual">
                  <option value="oklch">OKLCH</option>
                  <option value="oklab">OKLab</option>
                  <option value="lch">LCH</option>
                  <option value="lab">Lab</option>
                </optgroup>
                <optgroup label="RGB">
                  <option value="srgb">sRGB encoded</option>
                  <option value="srgb-linear">sRGB linear light</option>
                  <option value="p3">Display P3</option>
                </optgroup>
                <optgroup label="Cylindrical">
                  <option value="hsl">HSL</option>
                  <option value="hsv">HSV</option>
                </optgroup>
              </select>
            </label>
            <label className="field">
              <span className="field-label">Hue route</span>
              <select
                value={hue}
                onChange={(event) =>
                  commit({ hue: event.target.value as HueInterpolation })
                }
              >
                <option value="shorter">Shorter</option>
                <option value="longer">Longer</option>
                <option value="increasing">Increasing</option>
                <option value="decreasing">Decreasing</option>
                <option value="raw">Raw</option>
              </select>
            </label>
            <label className="field">
              <span className="field-label">Easing</span>
              <select
                value={easing}
                onChange={(event) =>
                  commit({ easing: event.target.value as EasingName })
                }
              >
                <option value="linear">Linear</option>
                <option value="ease-in">Ease in</option>
                <option value="ease-out">Ease out</option>
                <option value="ease-in-out">Ease in/out</option>
                <option value="smoothstep">Smoothstep</option>
              </select>
            </label>
            <label className="toggle-label alpha-mode-toggle">
              <input
                type="checkbox"
                checked={premultiplied}
                onChange={(event) =>
                  commit({ premultiplied: event.target.checked })
                }
              />
              <span>
                <strong>Premultiply alpha</strong>
                <small>Avoid transparent-colour fringes</small>
              </span>
            </label>
          </div>
        </section>
        <section className="panel ramp-panel">
          <div className="section-heading">
            <div>
              <h3>Generated ramp</h3>
              <p>
                {space.toUpperCase()} · {hue} hue · {easing} ·{" "}
                {premultiplied ? "premultiplied" : "straight"} alpha
              </p>
            </div>
            <div className="button-row">
              <CopyButton value={cssExport} label="Copy CSS" />
              <CopyButton value={jsonExport} label="Copy JSON" />
            </div>
          </div>
          <div className="gradient-preview checkerboard">
            <div style={{ background: gradient }} />
          </div>
          {calculation.error && (
            <p className="stale-notice" role="status">
              {calculation.error} Keeping the last valid ramp.
            </p>
          )}
          <div className="step-grid">
            {shownSteps.map((step, index) => (
              <article className="step-swatch" key={`${index}-${step.hex}`}>
                <button
                  type="button"
                  className="step-colour checkerboard"
                  style={{ "--swatch": step.css } as React.CSSProperties}
                  onClick={() => onAddColour(step.css, `Step ${index + 1}`)}
                  title="Add to palette"
                >
                  <span className="sr-only">
                    Add step {index + 1} to palette
                  </span>
                </button>
                <strong>{Math.round(step.position * 100)}%</strong>
                <code>{step.hex}</code>
                <CopyButton
                  value={step.css}
                  label={`Copy step ${index + 1}`}
                  compact
                />
              </article>
            ))}
          </div>
          <p className="field-help">
            Click a swatch to add it to your saved local palette. Premultiplied
            alpha prevents hidden transparent channels from tinting intermediate
            colours.
          </p>
        </section>
      </div>
    </div>
  );
 }
@@ -0,0 +1,30 @@
 import type { CSSProperties, ReactNode } from "react";
 export function Swatch({
  colour,
  label,
  detail,
  actions,
  large = false,
 }: {
  colour: string;
  label: string;
  detail?: string;
  actions?: ReactNode;
  large?: boolean;
 }) {
  return (
    <article className={`swatch-card${large ? " swatch-card--large" : ""}`}>
      <div
        className="swatch-colour checkerboard"
        style={{ "--swatch": colour } as CSSProperties}
        aria-label={`${label}: ${detail ?? colour}`}
      />
      <div className="swatch-meta">
        <strong>{label}</strong>
        <code>{detail ?? colour}</code>
      </div>
      {actions && <div className="swatch-actions">{actions}</div>}
    </article>
  );
 }
@@ -0,0 +1,156 @@
 import { useEffect, useMemo, useState } from "react";
 import { CompositeLab } from "./CompositeLab";
 import { ContrastLab } from "./ContrastLab";
 import { ConverterLab } from "./ConverterLab";
 import { ImagePickerLab } from "./ImagePickerLab";
 import { PaletteLab } from "./PaletteLab";
 import { PickerLab } from "./PickerLab";
 import { StepsLab } from "./StepsLab";
 import { useSavedPalette } from "../hooks/useSavedPalette";
 const workspaces = [
  { id: "convert", label: "Convert", short: "Spaces & syntax" },
  { id: "composite", label: "Composite", short: "RGBA layers" },
  { id: "steps", label: "Steps", short: "Interpolation" },
  { id: "pick", label: "Pick", short: "Visual picker" },
  { id: "image", label: "Image", short: "Sample & extract" },
  { id: "contrast", label: "Contrast", short: "Access & compare" },
  { id: "palette", label: "Palette", short: "Harmonies & tokens" },
 ] as const;
 type WorkspaceId = (typeof workspaces)[number]["id"];
 function initialWorkspace(): WorkspaceId {
  const fromHash = globalThis.location.hash.replace(/^#/, "") as WorkspaceId;
  return workspaces.some((workspace) => workspace.id === fromHash)
    ? fromHash
    : "convert";
 }
 export function Workbench() {
  const [active, setActive] = useState<WorkspaceId>(initialWorkspace);
  const palette = useSavedPalette();
  useEffect(() => {
    const onHash = () => setActive(initialWorkspace());
    globalThis.addEventListener("hashchange", onHash);
    return () => globalThis.removeEventListener("hashchange", onHash);
  }, []);
  useEffect(() => {
    document
      .getElementById(`tab-${active}`)
      ?.scrollIntoView({ block: "nearest", inline: "nearest" });
  }, [active]);
  function select(id: WorkspaceId) {
    setActive(id);
    history.replaceState(
      null,
      "",
      `${location.pathname}${location.search}#${id}`,
    );
  }
  const content = useMemo(() => {
    const onAddColour = (colour: string, name?: string) =>
      palette.addColour(colour, name);
    switch (active) {
      case "composite":
        return <CompositeLab onAddColour={onAddColour} />;
      case "steps":
        return <StepsLab onAddColour={onAddColour} />;
      case "pick":
        return <PickerLab onAddColour={onAddColour} />;
      case "image":
        return <ImagePickerLab onAddColour={onAddColour} />;
      case "contrast":
        return <ContrastLab onAddColour={onAddColour} />;
      case "palette":
        return <PaletteLab palette={palette} />;
      default:
        return <ConverterLab onAddColour={onAddColour} />;
    }
  }, [active, palette]);
  return (
    <main className="colour-workbench">
      <header className="workbench-intro">
        <div>
          <p className="eyebrow">Private by design</p>
          <h1>Colour workbench</h1>
          <p>
            Convert, layer, interpolate, sample and test colours without sending
            a byte away from your browser.
          </p>
        </div>
        <div
          className="privacy-badge"
          title="No uploads, analytics or server processing"
        >
          <svg aria-hidden="true" viewBox="0 0 24 24">
            <path d="M7 10V7a5 5 0 0 1 10 0v3m-11 0h12a2 2 0 0 1 2 2v7a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2v-7a2 2 0 0 1 2-2Zm6 4v3" />
          </svg>
          Local only
        </div>
      </header>
      <nav className="workspace-tabs" aria-label="Colour workspaces">
        <div role="tablist" aria-label="Colour workspaces">
          {workspaces.map((workspace) => (
            <button
              key={workspace.id}
              type="button"
              role="tab"
              id={`tab-${workspace.id}`}
              aria-controls={`panel-${workspace.id}`}
              aria-selected={active === workspace.id}
              tabIndex={active === workspace.id ? 0 : -1}
              onClick={() => select(workspace.id)}
              onKeyDown={(event) => {
                if (
                  !["ArrowLeft", "ArrowRight", "Home", "End"].includes(
                    event.key,
                  )
                )
                  return;
                event.preventDefault();
                const index = workspaces.findIndex(
                  (item) => item.id === active,
                );
                const nextIndex =
                  event.key === "Home"
                    ? 0
                    : event.key === "End"
                      ? workspaces.length - 1
                      : (index +
                          (event.key === "ArrowRight" ? 1 : -1) +
                          workspaces.length) %
                        workspaces.length;
                const next = workspaces[nextIndex];
                if (!next) return;
                select(next.id);
                requestAnimationFrame(() =>
                  document.getElementById(`tab-${next.id}`)?.focus(),
                );
              }}
            >
              <span>{workspace.label}</span>
              <small>{workspace.short}</small>
            </button>
          ))}
        </div>
      </nav>
      <section
        className="workspace-panel"
        role="tabpanel"
        id={`panel-${active}`}
        aria-labelledby={`tab-${active}`}
      >
        {content}
      </section>
    </main>
  );
 }
@@ -0,0 +1,97 @@
 import { useCallback, useEffect, useState } from "react";
 export interface SavedColour {
  id: string;
  name: string;
  value: string;
 }
 const STORAGE_KEY = "colour-tools.palette.v1";
 const LIMIT = 64;
 function readPalette(): SavedColour[] {
  try {
    const value = JSON.parse(
      localStorage.getItem(STORAGE_KEY) ?? "[]",
    ) as unknown;
    if (!Array.isArray(value)) return [];
    return value
      .filter(
        (entry): entry is SavedColour =>
          typeof entry === "object" &&
          entry !== null &&
          typeof (entry as SavedColour).id === "string" &&
          typeof (entry as SavedColour).name === "string" &&
          typeof (entry as SavedColour).value === "string",
      )
      .slice(0, LIMIT);
  } catch {
    return [];
  }
 }
 function makeId(): string {
  return globalThis.crypto?.randomUUID?.() ?? `${Date.now()}-${Math.random()}`;
 }
 export function useSavedPalette() {
  const [colours, setColours] = useState<SavedColour[]>(readPalette);
  useEffect(() => {
    try {
      localStorage.setItem(
        STORAGE_KEY,
        JSON.stringify(colours.slice(0, LIMIT)),
      );
    } catch {
      // Storage can be unavailable in private contexts; session state still works.
    }
  }, [colours]);
  const addColour = useCallback((value: string, name?: string) => {
    setColours((current) => {
      const duplicate = current.find(
        (entry) => entry.value.toLowerCase() === value.toLowerCase(),
      );
      if (duplicate) return current;
      return [
        ...current,
        {
          id: makeId(),
          name: name?.trim() || `Colour ${current.length + 1}`,
          value,
        },
      ].slice(-LIMIT);
    });
  }, []);
  const updateColour = useCallback(
    (id: string, update: Partial<Pick<SavedColour, "name" | "value">>) => {
      setColours((current) =>
        current.map((entry) =>
          entry.id === id ? { ...entry, ...update } : entry,
        ),
      );
    },
    [],
  );
  const removeColour = useCallback((id: string) => {
    setColours((current) => current.filter((entry) => entry.id !== id));
  }, []);
  const replaceColours = useCallback((next: SavedColour[]) => {
    setColours(next.slice(0, LIMIT));
  }, []);
  const clearColours = useCallback(() => setColours([]), []);
  return {
    colours,
    addColour,
    updateColour,
    removeColour,
    replaceColours,
    clearColours,
  };
 }
@@ -0,0 +1,20 @@
 import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
 import { App } from "./App";
 createRoot(document.getElementById("root")!).render(
  <StrictMode>
    <App />
  </StrictMode>,
 );
 if ("serviceWorker" in navigator && import.meta.env.PROD) {
  window.addEventListener("load", () => {
    const url = new URL("./sw.js", document.baseURI);
    void navigator.serviceWorker
      .register(url, { scope: new URL("./", document.baseURI).pathname })
      .catch(() => {
        // Offline installation is progressive enhancement.
      });
  });
 }
@@ -0,0 +1,170 @@
 import type { ImageLimits, PixelPoint } from "./types";
 const MEBIBYTE = 1024 * 1024;
 export const DEFAULT_IMAGE_LIMITS: ImageLimits = Object.freeze({
  maxBytes: 40 * MEBIBYTE,
  maxPixels: 24_000_000,
  maxDimension: 8_192,
  acceptedMimeTypes: Object.freeze([
    "image/png",
    "image/jpeg",
    "image/webp",
    "image/gif",
    "image/avif",
  ]),
 });
 export interface ValidationResult {
  readonly valid: boolean;
  readonly message?: string;
 }
 export const validateImageFile = (
  file: Pick<File, "name" | "size" | "type">,
  limits: ImageLimits = DEFAULT_IMAGE_LIMITS,
 ): ValidationResult => {
  if (file.size <= 0) {
    return { valid: false, message: "The selected image is empty." };
  }
  if (file.size > limits.maxBytes) {
    return {
      valid: false,
      message: `The selected image is larger than ${Math.round(limits.maxBytes / MEBIBYTE)} MiB.`,
    };
  }
  const mimeType = file.type.toLowerCase();
  const extension = file.name.toLowerCase().match(/\.([a-z0-9]+)$/)?.[1] ?? "";
  const extensionMimeType: Readonly<Record<string, string>> = {
    png: "image/png",
    jpg: "image/jpeg",
    jpeg: "image/jpeg",
    webp: "image/webp",
    gif: "image/gif",
    avif: "image/avif",
  };
  const detectedType = mimeType || extensionMimeType[extension] || "";
  if (!limits.acceptedMimeTypes.includes(detectedType)) {
    return {
      valid: false,
      message: "Choose a PNG, JPEG, WebP, GIF, or AVIF image.",
    };
  }
  return { valid: true };
 };
 export const validateImageDimensions = (
  width: number,
  height: number,
  limits: ImageLimits = DEFAULT_IMAGE_LIMITS,
 ): ValidationResult => {
  if (
    !Number.isSafeInteger(width) ||
    !Number.isSafeInteger(height) ||
    width <= 0 ||
    height <= 0
  ) {
    return { valid: false, message: "The image has invalid dimensions." };
  }
  if (width > limits.maxDimension || height > limits.maxDimension) {
    return {
      valid: false,
      message: `The image is too wide or tall. The limit is ${limits.maxDimension.toLocaleString()} pixels per side.`,
    };
  }
  if (width * height > limits.maxPixels) {
    return {
      valid: false,
      message: `The decoded image is too large. The limit is ${limits.maxPixels.toLocaleString()} pixels.`,
    };
  }
  return { valid: true };
 };
 export interface ClientRectLike {
  readonly left: number;
  readonly top: number;
  readonly width: number;
  readonly height: number;
 }
 export const mapClientPointToPixel = (
  clientX: number,
  clientY: number,
  rect: ClientRectLike,
  imageWidth: number,
  imageHeight: number,
 ): PixelPoint | null => {
  if (
    !Number.isFinite(rect.left) ||
    !Number.isFinite(rect.top) ||
    !Number.isFinite(rect.width) ||
    !Number.isFinite(rect.height) ||
    rect.width <= 0 ||
    rect.height <= 0 ||
    !Number.isSafeInteger(imageWidth) ||
    !Number.isSafeInteger(imageHeight) ||
    imageWidth <= 0 ||
    imageHeight <= 0 ||
    !Number.isFinite(clientX) ||
    !Number.isFinite(clientY)
  ) {
    return null;
  }
  const relativeX = (clientX - rect.left) / rect.width;
  const relativeY = (clientY - rect.top) / rect.height;
  const x = Math.min(
    imageWidth - 1,
    Math.max(0, Math.floor(relativeX * imageWidth)),
  );
  const y = Math.min(
    imageHeight - 1,
    Math.max(0, Math.floor(relativeY * imageHeight)),
  );
  return { x, y };
 };
 export interface SampleRegion {
  readonly left: number;
  readonly top: number;
  readonly width: number;
  readonly height: number;
  readonly centerX: number;
  readonly centerY: number;
 }
 export const getBoundedSampleRegion = (
  x: number,
  y: number,
  radius: number,
  imageWidth: number,
  imageHeight: number,
 ): SampleRegion | null => {
  if (
    imageWidth <= 0 ||
    imageHeight <= 0 ||
    !Number.isFinite(x) ||
    !Number.isFinite(y) ||
    !Number.isFinite(radius)
  ) {
    return null;
  }
  const safeX = Math.min(imageWidth - 1, Math.max(0, Math.round(x)));
  const safeY = Math.min(imageHeight - 1, Math.max(0, Math.round(y)));
  const safeRadius = Math.min(64, Math.max(0, Math.round(radius)));
  const left = Math.max(0, safeX - safeRadius);
  const top = Math.max(0, safeY - safeRadius);
  const right = Math.min(imageWidth - 1, safeX + safeRadius);
  const bottom = Math.min(imageHeight - 1, safeY + safeRadius);
  return {
    left,
    top,
    width: right - left + 1,
    height: bottom - top + 1,
    centerX: safeX - left,
    centerY: safeY - top,
  };
 };
@@ -0,0 +1,91 @@
 export interface DecodedLocalImage {
  readonly source: CanvasImageSource;
  readonly width: number;
  readonly height: number;
  dispose: () => void;
 }
 const abortError = (): DOMException =>
  new DOMException("Image decoding was cancelled.", "AbortError");
 const decodeWithImageElement = (
  file: File,
  signal?: AbortSignal,
 ): Promise<DecodedLocalImage> =>
  new Promise((resolve, reject) => {
    if (signal?.aborted) {
      reject(abortError());
      return;
    }
    const objectUrl = URL.createObjectURL(file);
    const image = new Image();
    image.decoding = "async";
    let settled = false;
    const cleanup = (): void => {
      image.onload = null;
      image.onerror = null;
      signal?.removeEventListener("abort", onAbort);
      URL.revokeObjectURL(objectUrl);
    };
    const onAbort = (): void => {
      if (settled) return;
      settled = true;
      image.src = "";
      cleanup();
      reject(abortError());
    };
    image.onload = () => {
      if (settled) return;
      settled = true;
      cleanup();
      resolve({
        source: image,
        width: image.naturalWidth,
        height: image.naturalHeight,
        dispose: () => {
          image.src = "";
        },
      });
    };
    image.onerror = () => {
      if (settled) return;
      settled = true;
      cleanup();
      reject(new Error("The browser could not decode this image."));
    };
    signal?.addEventListener("abort", onAbort, { once: true });
    image.src = objectUrl;
  });
 export const decodeLocalImage = async (
  file: File,
  signal?: AbortSignal,
 ): Promise<DecodedLocalImage> => {
  if (signal?.aborted) throw abortError();
  if (typeof createImageBitmap === "function") {
    try {
      const bitmap = await createImageBitmap(file, {
        imageOrientation: "from-image",
      });
      if (signal?.aborted) {
        bitmap.close();
        throw abortError();
      }
      return {
        source: bitmap,
        width: bitmap.width,
        height: bitmap.height,
        dispose: () => bitmap.close(),
      };
    } catch (error) {
      if (
        signal?.aborted ||
        (error instanceof DOMException && error.name === "AbortError")
      )
        throw error;
      // Older browsers sometimes expose createImageBitmap without supporting every format.
    }
  }
  return decodeWithImageElement(file, signal);
 };
@@ -0,0 +1,224 @@
 import { rgbaToCss, rgbaToHex } from "./format";
 import {
  oklabDistanceSquared,
  oklabToRgb,
  rgbToOklab,
  type Oklab,
 } from "./oklab";
 import type {
  ExtractedPaletteColour,
  PaletteExtractionOptions,
  PixelBuffer,
 } from "./types";
 interface ColourPoint extends Oklab {
  readonly key: number;
  readonly weight: number;
  readonly population: number;
 }
 interface MutableCluster {
  l: number;
  a: number;
  b: number;
  weight: number;
  population: number;
 }
 const clampInteger = (
  value: number | undefined,
  fallback: number,
  minimum: number,
  maximum: number,
 ): number => {
  if (value === undefined || !Number.isFinite(value)) return fallback;
  return Math.min(maximum, Math.max(minimum, Math.round(value)));
 };
 const makePoints = (
  pixels: PixelBuffer,
  maximumSamples: number,
  minimumAlpha: number,
 ): ColourPoint[] => {
  const totalPixels = pixels.width * pixels.height;
  const stride = Math.max(1, Math.ceil(totalPixels / maximumSamples));
  const histogram = new Map<number, { weight: number; population: number }>();
  for (let pixel = 0; pixel < totalPixels; pixel += stride) {
    const offset = pixel * 4;
    const alpha = pixels.data[offset + 3] ?? 0;
    if (alpha < minimumAlpha || alpha === 0) continue;
    const red = pixels.data[offset] ?? 0;
    const green = pixels.data[offset + 1] ?? 0;
    const blue = pixels.data[offset + 2] ?? 0;
    const key = (red << 16) | (green << 8) | blue;
    const entry = histogram.get(key) ?? { weight: 0, population: 0 };
    entry.weight += alpha / 255;
    entry.population += 1;
    histogram.set(key, entry);
  }
  return [...histogram.entries()]
    .sort(([left], [right]) => left - right)
    .map(([key, entry]) => {
      const red = (key >> 16) & 0xff;
      const green = (key >> 8) & 0xff;
      const blue = key & 0xff;
      return { key, ...rgbToOklab(red, green, blue), ...entry };
    });
 };
 const selectInitialCentroids = (
  points: readonly ColourPoint[],
  count: number,
 ): Oklab[] => {
  if (points.length === 0) return [];
  const first = points.reduce((best, point) => {
    if (point.weight > best.weight) return point;
    return point.weight === best.weight && point.key < best.key ? point : best;
  });
  const centroids: Oklab[] = [{ l: first.l, a: first.a, b: first.b }];
  const selected = new Set([first.key]);
  while (centroids.length < count) {
    let bestPoint: ColourPoint | null = null;
    let bestScore = -1;
    for (const point of points) {
      if (selected.has(point.key)) continue;
      let closestDistance = Number.POSITIVE_INFINITY;
      for (const centroid of centroids) {
        closestDistance = Math.min(
          closestDistance,
          oklabDistanceSquared(point, centroid),
        );
      }
      const score = closestDistance * Math.sqrt(point.weight);
      if (
        score > bestScore ||
        (score === bestScore &&
          (bestPoint === null || point.key < bestPoint.key))
      ) {
        bestPoint = point;
        bestScore = score;
      }
    }
    if (bestPoint === null) break;
    selected.add(bestPoint.key);
    centroids.push({ l: bestPoint.l, a: bestPoint.a, b: bestPoint.b });
  }
  return centroids;
 };
 const nearestCentroid = (point: Oklab, centroids: readonly Oklab[]): number => {
  let nearest = 0;
  let nearestDistance = Number.POSITIVE_INFINITY;
  for (let index = 0; index < centroids.length; index += 1) {
    const centroid = centroids[index];
    if (!centroid) continue;
    const distance = oklabDistanceSquared(point, centroid);
    if (distance < nearestDistance) {
      nearest = index;
      nearestDistance = distance;
    }
  }
  return nearest;
 };
 const emptyClusters = (count: number): MutableCluster[] =>
  Array.from({ length: count }, () => ({
    l: 0,
    a: 0,
    b: 0,
    weight: 0,
    population: 0,
  }));
 const accumulate = (
  points: readonly ColourPoint[],
  centroids: readonly Oklab[],
 ): MutableCluster[] => {
  const clusters = emptyClusters(centroids.length);
  for (const point of points) {
    const cluster = clusters[nearestCentroid(point, centroids)];
    if (!cluster) continue;
    cluster.l += point.l * point.weight;
    cluster.a += point.a * point.weight;
    cluster.b += point.b * point.weight;
    cluster.weight += point.weight;
    cluster.population += point.population;
  }
  return clusters;
 };
 export const extractPalette = (
  pixels: PixelBuffer,
  options: PaletteExtractionOptions,
 ): ExtractedPaletteColour[] => {
  if (
    !Number.isSafeInteger(pixels.width) ||
    !Number.isSafeInteger(pixels.height) ||
    pixels.width <= 0 ||
    pixels.height <= 0 ||
    !Number.isSafeInteger(pixels.width * pixels.height) ||
    pixels.data.length < pixels.width * pixels.height * 4
  ) {
    throw new Error("Invalid pixel buffer.");
  }
  const requestedCount = clampInteger(options.count, 6, 2, 12);
  const maximumSamples = clampInteger(options.maxSamples, 80_000, 1, 200_000);
  const maximumIterations = clampInteger(options.maxIterations, 24, 1, 64);
  const minimumAlpha = clampInteger(options.minimumAlpha, 16, 0, 255);
  const points = makePoints(pixels, maximumSamples, minimumAlpha);
  if (points.length === 0) return [];
  let centroids = selectInitialCentroids(
    points,
    Math.min(requestedCount, points.length),
  );
  for (let iteration = 0; iteration < maximumIterations; iteration += 1) {
    const clusters = accumulate(points, centroids);
    let maximumShift = 0;
    const nextCentroids = centroids.map((centroid, index) => {
      const cluster = clusters[index];
      if (!cluster || cluster.weight <= 0) return centroid;
      const next = {
        l: cluster.l / cluster.weight,
        a: cluster.a / cluster.weight,
        b: cluster.b / cluster.weight,
      };
      maximumShift = Math.max(
        maximumShift,
        oklabDistanceSquared(centroid, next),
      );
      return next;
    });
    centroids = nextCentroids;
    if (maximumShift < 1e-10) break;
  }
  const clusters = accumulate(points, centroids);
  const totalWeight = clusters.reduce(
    (sum, cluster) => sum + cluster.weight,
    0,
  );
  return clusters
    .map((cluster, index): ExtractedPaletteColour | null => {
      const centroid = centroids[index];
      if (!centroid || cluster.weight <= 0 || totalWeight <= 0) return null;
      const rgb = oklabToRgb(centroid);
      const colour = { ...rgb, a: 255 };
      return {
        ...colour,
        hex: rgbaToHex(colour),
        css: rgbaToCss(colour),
        coverage: cluster.weight / totalWeight,
        population: cluster.population,
      };
    })
    .filter((colour): colour is ExtractedPaletteColour => colour !== null)
    .sort(
      (left, right) =>
        right.coverage - left.coverage || left.hex.localeCompare(right.hex),
    );
 };
@@ -0,0 +1,21 @@
 import type { Rgba8 } from "./types";
 const byteToHex = (value: number): string =>
  Math.round(Math.max(0, Math.min(255, value)))
    .toString(16)
    .padStart(2, "0")
    .toUpperCase();
 export const rgbaToHex = (
  colour: Rgba8,
  includeAlpha = colour.a < 255,
 ): string =>
  `#${byteToHex(colour.r)}${byteToHex(colour.g)}${byteToHex(colour.b)}${includeAlpha ? byteToHex(colour.a) : ""}`;
 export const rgbaToCss = (colour: Rgba8): string => {
  const alpha = Math.max(0, Math.min(255, colour.a)) / 255;
  if (alpha >= 1) {
    return `rgb(${Math.round(colour.r)} ${Math.round(colour.g)} ${Math.round(colour.b)})`;
  }
  return `rgb(${Math.round(colour.r)} ${Math.round(colour.g)} ${Math.round(colour.b)} / ${Number(alpha.toFixed(3))})`;
 };
@@ -0,0 +1,23 @@
 export {
  DEFAULT_IMAGE_LIMITS,
  getBoundedSampleRegion,
  mapClientPointToPixel,
  validateImageDimensions,
  validateImageFile,
 } from "./bounds";
 export { extractPalette } from "./extract";
 export { decodeLocalImage } from "./decode";
 export { rgbaToCss, rgbaToHex } from "./format";
 export { samplePixels } from "./sample";
 export type {
  ExtractedPaletteColour,
  ImageLimits,
  LoadedImageDetails,
  PaletteExtractionOptions,
  PixelBuffer,
  PixelPoint,
  PixelSample,
  Rgba8,
  SamplingMethod,
 } from "./types";
 export { extractPaletteSafely } from "./worker-client";
@@ -0,0 +1,64 @@
 interface Oklab {
  readonly l: number;
  readonly a: number;
  readonly b: number;
 }
 const srgbToLinear = (channel: number): number => {
  const value = Math.max(0, Math.min(255, channel)) / 255;
  return value <= 0.04045 ? value / 12.92 : ((value + 0.055) / 1.055) ** 2.4;
 };
 const linearToSrgb = (channel: number): number => {
  const value =
    channel <= 0.0031308
      ? 12.92 * channel
      : 1.055 * channel ** (1 / 2.4) - 0.055;
  return Math.round(Math.max(0, Math.min(1, value)) * 255);
 };
 export const rgbToOklab = (red: number, green: number, blue: number): Oklab => {
  const r = srgbToLinear(red);
  const g = srgbToLinear(green);
  const b = srgbToLinear(blue);
  const lRoot = Math.cbrt(
    0.4122214708 * r + 0.5363325363 * g + 0.0514459929 * b,
  );
  const mRoot = Math.cbrt(
    0.2119034982 * r + 0.6806995451 * g + 0.1073969566 * b,
  );
  const sRoot = Math.cbrt(
    0.0883024619 * r + 0.2817188376 * g + 0.6299787005 * b,
  );
  return {
    l: 0.2104542553 * lRoot + 0.793617785 * mRoot - 0.0040720468 * sRoot,
    a: 1.9779984951 * lRoot - 2.428592205 * mRoot + 0.4505937099 * sRoot,
    b: 0.0259040371 * lRoot + 0.7827717662 * mRoot - 0.808675766 * sRoot,
  };
 };
 export const oklabToRgb = (lab: Oklab): { r: number; g: number; b: number } => {
  const lRoot = lab.l + 0.3963377774 * lab.a + 0.2158037573 * lab.b;
  const mRoot = lab.l - 0.1055613458 * lab.a - 0.0638541728 * lab.b;
  const sRoot = lab.l - 0.0894841775 * lab.a - 1.291485548 * lab.b;
  const l = lRoot ** 3;
  const m = mRoot ** 3;
  const s = sRoot ** 3;
  return {
    r: linearToSrgb(4.0767416621 * l - 3.3077115913 * m + 0.2309699292 * s),
    g: linearToSrgb(-1.2684380046 * l + 2.6097574011 * m - 0.3413193965 * s),
    b: linearToSrgb(-0.0041960863 * l - 0.7034186147 * m + 1.707614701 * s),
  };
 };
 export const oklabDistanceSquared = (left: Oklab, right: Oklab): number => {
  const dl = left.l - right.l;
  const da = left.a - right.a;
  const db = left.b - right.b;
  return dl * dl + da * da + db * db;
 };
 export type { Oklab };
@@ -0,0 +1,114 @@
 import { rgbaToCss, rgbaToHex } from "./format";
 import type { PixelBuffer, PixelSample, SamplingMethod } from "./types";
 const median = (values: number[]): number => {
  if (values.length === 0) return 0;
  values.sort((left, right) => left - right);
  const middle = Math.floor(values.length / 2);
  if (values.length % 2 === 1) return values[middle] ?? 0;
  return ((values[middle - 1] ?? 0) + (values[middle] ?? 0)) / 2;
 };
 export const samplePixels = (
  pixels: PixelBuffer,
  x: number,
  y: number,
  radius: number,
  method: SamplingMethod,
 ): PixelSample | null => {
  const { data, width, height } = pixels;
  const safeX = Math.round(x);
  const safeY = Math.round(y);
  if (
    !Number.isSafeInteger(width) ||
    !Number.isSafeInteger(height) ||
    width <= 0 ||
    height <= 0 ||
    !Number.isSafeInteger(width * height) ||
    data.length < width * height * 4 ||
    !Number.isFinite(safeX) ||
    !Number.isFinite(safeY) ||
    safeX < 0 ||
    safeX >= width ||
    safeY < 0 ||
    safeY >= height
  ) {
    return null;
  }
  const safeRadius = Math.min(64, Math.max(0, Math.round(radius)));
  const red: number[] = [];
  const green: number[] = [];
  const blue: number[] = [];
  const alpha: number[] = [];
  let alphaWeight = 0;
  let weightedRed = 0;
  let weightedGreen = 0;
  let weightedBlue = 0;
  let alphaTotal = 0;
  const radiusSquared = safeRadius * safeRadius;
  for (
    let row = Math.max(0, safeY - safeRadius);
    row <= Math.min(height - 1, safeY + safeRadius);
    row += 1
  ) {
    for (
      let column = Math.max(0, safeX - safeRadius);
      column <= Math.min(width - 1, safeX + safeRadius);
      column += 1
    ) {
      const dx = column - safeX;
      const dy = row - safeY;
      if (safeRadius > 0 && dx * dx + dy * dy > radiusSquared) continue;
      const offset = (row * width + column) * 4;
      const r = data[offset] ?? 0;
      const g = data[offset + 1] ?? 0;
      const b = data[offset + 2] ?? 0;
      const a = data[offset + 3] ?? 0;
      const weight = a / 255;
      alpha.push(a);
      alphaTotal += a;
      alphaWeight += weight;
      weightedRed += r * weight;
      weightedGreen += g * weight;
      weightedBlue += b * weight;
      if (a > 0) {
        red.push(r);
        green.push(g);
        blue.push(b);
      }
    }
  }
  if (alpha.length === 0) return null;
  const colour =
    method === "median"
      ? {
          r: Math.round(median(red)),
          g: Math.round(median(green)),
          b: Math.round(median(blue)),
          a: Math.round(median(alpha)),
        }
      : {
          r: Math.round(alphaWeight > 0 ? weightedRed / alphaWeight : 0),
          g: Math.round(alphaWeight > 0 ? weightedGreen / alphaWeight : 0),
          b: Math.round(alphaWeight > 0 ? weightedBlue / alphaWeight : 0),
          a: Math.round(alphaTotal / alpha.length),
        };
  return {
    ...colour,
    x: safeX,
    y: safeY,
    radius: safeRadius,
    method,
    pixelCount: alpha.length,
    hex: rgbaToHex(colour),
    css: rgbaToCss(colour),
  };
 };
@@ -0,0 +1,56 @@
 export type SamplingMethod = "average" | "median";
 export interface Rgba8 {
  readonly r: number;
  readonly g: number;
  readonly b: number;
  readonly a: number;
 }
 export interface PixelBuffer {
  readonly data: Uint8ClampedArray;
  readonly width: number;
  readonly height: number;
 }
 export interface PixelPoint {
  readonly x: number;
  readonly y: number;
 }
 export interface PixelSample extends Rgba8, PixelPoint {
  readonly method: SamplingMethod;
  readonly radius: number;
  readonly pixelCount: number;
  readonly hex: string;
  readonly css: string;
 }
 export interface PaletteExtractionOptions {
  readonly count: number;
  readonly maxSamples?: number;
  readonly maxIterations?: number;
  readonly minimumAlpha?: number;
 }
 export interface ExtractedPaletteColour extends Rgba8 {
  readonly hex: string;
  readonly css: string;
  readonly coverage: number;
  readonly population: number;
 }
 export interface ImageLimits {
  readonly maxBytes: number;
  readonly maxPixels: number;
  readonly maxDimension: number;
  readonly acceptedMimeTypes: readonly string[];
 }
 export interface LoadedImageDetails {
  readonly name: string;
  readonly mimeType: string;
  readonly bytes: number;
  readonly width: number;
  readonly height: number;
 }
@@ -0,0 +1,102 @@
 import { extractPalette } from "./extract";
 import type {
  ExtractedPaletteColour,
  PaletteExtractionOptions,
  PixelBuffer,
 } from "./types";
 interface PaletteWorkerSuccess {
  readonly id: number;
  readonly ok: true;
  readonly palette: ExtractedPaletteColour[];
 }
 interface PaletteWorkerFailure {
  readonly id: number;
  readonly ok: false;
  readonly message: string;
 }
 type PaletteWorkerResponse = PaletteWorkerSuccess | PaletteWorkerFailure;
 let requestSequence = 0;
 const abortError = (): DOMException =>
  new DOMException("Palette extraction was cancelled.", "AbortError");
 const extractWithWorker = (
  pixels: PixelBuffer,
  options: PaletteExtractionOptions,
  signal?: AbortSignal,
 ): Promise<ExtractedPaletteColour[]> =>
  new Promise((resolve, reject) => {
    if (typeof Worker === "undefined") {
      reject(new Error("Web Workers are unavailable."));
      return;
    }
    if (signal?.aborted) {
      reject(abortError());
      return;
    }
    const id = ++requestSequence;
    const bytes = new Uint8ClampedArray(pixels.data);
    const worker = new Worker(
      new URL("../workers/palette.worker.ts", import.meta.url),
      { type: "module" },
    );
    const timeout = window.setTimeout(() => {
      worker.terminate();
      reject(new Error("Palette worker timed out."));
    }, 12_000);
    const finish = (): void => {
      window.clearTimeout(timeout);
      worker.terminate();
      signal?.removeEventListener("abort", onAbort);
    };
    const onAbort = (): void => {
      finish();
      reject(abortError());
    };
    worker.onmessage = (event: MessageEvent<PaletteWorkerResponse>) => {
      if (event.data.id !== id) return;
      finish();
      if (event.data.ok) resolve(event.data.palette);
      else reject(new Error(event.data.message));
    };
    worker.onerror = () => {
      finish();
      reject(new Error("Palette worker failed."));
    };
    signal?.addEventListener("abort", onAbort, { once: true });
    worker.postMessage(
      {
        id,
        width: pixels.width,
        height: pixels.height,
        bytes: bytes.buffer,
        options,
      },
      [bytes.buffer],
    );
  });
 export const extractPaletteSafely = async (
  pixels: PixelBuffer,
  options: PaletteExtractionOptions,
  signal?: AbortSignal,
 ): Promise<ExtractedPaletteColour[]> => {
  try {
    return await extractWithWorker(pixels, options, signal);
  } catch (error) {
    if (
      signal?.aborted ||
      (error instanceof DOMException && error.name === "AbortError")
    )
      throw error;
    // Extraction inputs are deliberately bounded, so a synchronous fallback remains safe.
    return extractPalette(pixels, options);
  }
 };
@@ -0,0 +1,25 @@
 import "@testing-library/jest-dom/vitest";
 import { cleanup } from "@testing-library/react";
 import { afterEach } from "vitest";
 afterEach(cleanup);
 if (!HTMLDialogElement.prototype.showModal) {
  HTMLDialogElement.prototype.showModal = function showModal() {
    this.setAttribute("open", "");
  };
 }
 if (!HTMLDialogElement.prototype.close) {
  HTMLDialogElement.prototype.close = function close() {
    this.removeAttribute("open");
    this.dispatchEvent(new Event("close"));
  };
 }
 if (!URL.createObjectURL) URL.createObjectURL = () => "blob:test";
 if (!URL.revokeObjectURL) URL.revokeObjectURL = () => undefined;
 if (!Element.prototype.scrollIntoView) {
  Element.prototype.scrollIntoView = () => undefined;
 }
@@ -0,0 +1,51 @@
 {
  "$schema": "https://git.add-ideas.de/lotobo/toolbox-sdk/raw/branch/main/schemas/toolbox-app.v1.schema.json",
  "schemaVersion": 1,
  "id": "de.add-ideas.colour-tools",
  "name": "Colour Tools",
  "version": "0.1.0",
  "description": "Convert, composite, compare and build colours locally in the browser.",
  "entry": "./",
  "icon": "./favicon.svg",
  "categories": ["graphics", "design", "developer"],
  "tags": [
    "colour",
    "color",
    "rgb",
    "rgba",
    "oklch",
    "palette",
    "gradient",
    "contrast",
    "image"
  ],
  "integration": {
    "contextVersion": 1,
    "launchModes": ["navigate", "new-tab"],
    "embedding": "unsupported"
  },
  "requirements": {
    "secureContext": false,
    "workers": true,
    "indexedDb": false,
    "crossOriginIsolated": false,
    "topLevelContext": false
  },
  "privacy": {
    "processing": "local",
    "fileUploads": false,
    "telemetry": false,
    "label": "Colours and images stay in this browser; nothing is uploaded."
  },
  "source": {
    "repository": "https://git.add-ideas.de/lotobo/colour-tools",
    "license": "GPL-3.0-or-later"
  },
  "actions": [
    {
      "id": "source",
      "label": "Source",
      "url": "https://git.add-ideas.de/lotobo/colour-tools"
    }
  ]
 }
@@ -0,0 +1,4 @@
 import { defineToolboxApp, parseToolboxApp } from "@add-ideas/toolbox-contract";
 import source from "./manifest.source.json";
 export const manifest = defineToolboxApp(parseToolboxApp(source));
@@ -0,0 +1 @@
 export const APP_VERSION = "0.1.0";
@@ -0,0 +1 @@
 /// <reference types="vite/client" />
@@ -0,0 +1,31 @@
 /// <reference lib="webworker" />
 import { extractPalette } from "../palette/extract";
 import type { PaletteExtractionOptions } from "../palette/types";
 interface PaletteWorkerRequest {
  readonly id: number;
  readonly width: number;
  readonly height: number;
  readonly bytes: ArrayBuffer;
  readonly options: PaletteExtractionOptions;
 }
 const workerScope = self as DedicatedWorkerGlobalScope;
 workerScope.onmessage = (event: MessageEvent<PaletteWorkerRequest>) => {
  const { id, width, height, bytes, options } = event.data;
  try {
    const palette = extractPalette(
      { data: new Uint8ClampedArray(bytes), width, height },
      options,
    );
    workerScope.postMessage({ id, ok: true, palette });
  } catch (error) {
    const message =
      error instanceof Error ? error.message : "Palette extraction failed.";
    workerScope.postMessage({ id, ok: false, message });
  }
 };
 export {};
@@ -0,0 +1,201 @@
 import { expect, test, type Page } from "@playwright/test";
 const APP_ORIGIN = "http://127.0.0.1:4173";
 const FOUR_COLOUR_PNG =
  "iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAYAAABytg0kAAAAE0lEQVR4nGP4z8DwHwwZGP6DAQBJyAn3FGMynQAAAABJRU5ErkJggg==";
 async function keepNetworkLocal(page: Page): Promise<string[]> {
  const externalRequests: string[] = [];
  await page.route("**/*", async (route) => {
    const requestUrl = new URL(route.request().url());
    if (requestUrl.origin !== APP_ORIGIN) {
      externalRequests.push(requestUrl.href);
      await route.abort();
      return;
    }
    await route.continue();
  });
  return externalRequests;
 }
 function recordRuntimeErrors(page: Page): string[] {
  const runtimeErrors: string[] = [];
  page.on("pageerror", (error) => runtimeErrors.push(error.message));
  page.on("console", (message) => {
    if (message.type() === "error") runtimeErrors.push(message.text());
  });
  return runtimeErrors;
 }
 test("converts, composites and interpolates without transient empty results", async ({
  page,
 }) => {
  const runtimeErrors = recordRuntimeErrors(page);
  const externalRequests = await keepNetworkLocal(page);
  await page.goto("/deep/nested/colour/");
  await expect(
    page.getByRole("heading", { name: "Colour workbench" }),
  ).toBeVisible();
  await expect(
    page.getByRole("heading", { name: "Convert colours" }),
  ).toBeVisible();
  await page.getByLabel("Colour", { exact: true }).fill("rgb(255 0 0 / 50%)");
  const alphaHex = page
    .locator(".conversion-row")
    .filter({ hasText: "HEX + alpha" });
  await expect(alphaHex).toContainText("#ff000080");
  await page.getByLabel("Colour", { exact: true }).fill("rgb(255 0");
  await expect(
    page.getByText(
      "Keeping the last valid conversion while you finish editing.",
    ),
  ).toBeVisible();
  await expect(alphaHex).toContainText("#ff000080");
  await page.getByRole("tab", { name: /Composite/u }).click();
  await expect(
    page.getByRole("heading", { name: "Composite translucent colours" }),
  ).toBeVisible();
  await expect(page.locator(".layer-row")).toHaveCount(3);
  await page.getByRole("button", { name: "+ Add layer" }).click();
  await expect(page.locator(".layer-row")).toHaveCount(4);
  await expect(page.locator(".result-values code").first()).not.toBeEmpty();
  await page.getByRole("tab", { name: /Steps/u }).click();
  await expect(
    page.getByRole("heading", { name: "Step between colours" }),
  ).toBeVisible();
  await expect(page.locator(".step-swatch")).toHaveCount(9);
  await page.getByLabel(/Swatches/u).fill("5");
  await expect(page.locator(".step-swatch")).toHaveCount(5);
  expect(externalRequests).toEqual([]);
  expect(runtimeErrors).toEqual([]);
 });
 test("keeps picking, accessibility analysis and palette data browser-local", async ({
  page,
 }) => {
  const runtimeErrors = recordRuntimeErrors(page);
  const externalRequests = await keepNetworkLocal(page);
  await page.goto("/deep/nested/colour/#pick");
  await expect(
    page.getByRole("heading", { name: "Pick a colour" }),
  ).toBeVisible();
  const picker = page.getByRole("application");
  await expect(picker).toHaveAccessibleName(/Saturation 62 percent/u);
  await picker.focus();
  await picker.press("ArrowRight");
  await expect(picker).toHaveAccessibleName(/Saturation 63 percent/u);
  await page.getByLabel("Exact CSS colour").fill("oklch(70% 0.2 30)");
  await page.getByRole("button", { name: "Add to palette" }).click();
  await page.getByRole("tab", { name: /Contrast/u }).click();
  await expect(
    page.getByRole("heading", { name: "Contrast & compare" }),
  ).toBeVisible();
  await page
    .getByRole("textbox", { name: "Foreground", exact: true })
    .fill("#000000");
  await page
    .getByRole("textbox", { name: "Background", exact: true })
    .fill("#ffffff");
  await expect(page.locator(".ratio-heading strong")).toHaveText("21.00");
  await expect(
    page.getByText("AAA normal text", { exact: true }),
  ).toBeVisible();
  await page.getByRole("tab", { name: /Palette/u }).click();
  await expect(
    page.getByRole("heading", { name: "Build a palette" }),
  ).toBeVisible();
  await page
    .getByLabel("Palette data")
    .fill("primary: #123456\naccent: oklch(76% 0.17 87)");
  await page.getByRole("button", { name: "Import colours" }).click();
  await expect(page.getByRole("status")).toContainText("Added 2 colours");
  await expect(page.locator(".saved-colour-list > li")).toHaveCount(3);
  await expect(page.locator(".export-preview")).toContainText(
    "--brand-primary",
  );
  await page.reload();
  await page.getByRole("tab", { name: /Palette/u }).click();
  await expect(page.locator(".saved-colour-list > li")).toHaveCount(3);
  expect(externalRequests).toEqual([]);
  expect(runtimeErrors).toEqual([]);
 });
 test("loads, samples and extracts a palette from an in-memory image", async ({
  page,
 }) => {
  const runtimeErrors = recordRuntimeErrors(page);
  const externalRequests = await keepNetworkLocal(page);
  await page.goto("/deep/nested/colour/#image");
  await expect(
    page.getByRole("heading", { name: "Pick and extract colours" }),
  ).toBeVisible();
  await page.locator('input[type="file"]').evaluate((element, encoded) => {
    const bytes = Uint8Array.from(atob(encoded), (character) =>
      character.charCodeAt(0),
    );
    const transfer = new DataTransfer();
    transfer.items.add(
      new File([bytes], "four-colours.png", { type: "image/png" }),
    );
    const input = element as HTMLInputElement;
    input.files = transfer.files;
    input.dispatchEvent(new Event("change", { bubbles: true }));
  }, FOUR_COLOUR_PNG);
  await expect(page.locator(".image-picker-lab__status")).toContainText(
    "four-colours.png loaded: 2 by 2 pixels",
  );
  await page.getByRole("button", { name: "Sample coordinate" }).click();
  await expect(page.getByLabel("Sampled colour #FF0000")).toBeVisible();
  await page.getByRole("button", { name: "Extract palette" }).click();
  await expect(
    page.getByRole("list", { name: "Extracted image palette" }),
  ).toBeVisible({ timeout: 30_000 });
  expect(
    await page
      .getByRole("list", { name: "Extracted image palette" })
      .getByRole("listitem")
      .count(),
  ).toBeGreaterThanOrEqual(2);
  await page.getByRole("button", { name: "Remove image" }).click();
  await expect(page.locator(".image-picker-lab__status")).toContainText(
    "Image removed",
  );
  expect(externalRequests).toEqual([]);
  expect(runtimeErrors).toEqual([]);
 });
 test("serves a relocatable production artifact with hardened headers", async ({
  request,
 }) => {
  const index = await request.get("/deep/nested/colour/");
  expect(index.ok()).toBe(true);
  expect(index.headers()["content-security-policy"]).toContain(
    "default-src 'self'",
  );
  expect(index.headers()["x-content-type-options"]).toBe("nosniff");
  expect(await index.text()).not.toMatch(/\b(?:src|href)=["']\//u);
  const manifest = await request.get("/deep/nested/colour/toolbox-app.json");
  expect(manifest.headers()["content-type"]).toContain("application/json");
  await expect(manifest.json()).resolves.toMatchObject({
    id: "de.add-ideas.colour-tools",
    version: "0.1.0",
    entry: "./",
    icon: "./favicon.svg",
  });
 });
@@ -0,0 +1,111 @@
 import { describe, expect, it } from "vitest";
 import {
  colourHarmony,
  deltaE,
  exportPalette,
  formatColour,
  normaliseTokenName,
  parsePaletteList,
  shades,
  simulateColourVision,
  simulateColourVisionSet,
  tints,
  tones,
 } from "../../src/colour";
 describe("comparison and colour-vision tools", () => {
  it("provides standard Delta-E methods", () => {
    expect(deltaE("#f8f5ee", "#f8f5ee", "2000")).toBe(0);
    expect(deltaE("red", "blue", "76")).toBeGreaterThan(100);
    expect(deltaE("#777", "#787878", "ok")).toBeGreaterThan(0);
  });
  it("simulates four deficiencies while preserving alpha", () => {
    const original = "rgba(200, 40, 20, .4)";
    const unchanged = simulateColourVision(original, "deuteranopia", {
      severity: 0,
    });
    expect(formatColour(unchanged, "hex8")).toBe("#c8281466");
    const simulated = simulateColourVision(original, "deuteranopia");
    expect(simulated.alpha).toBeCloseTo(0.4);
    expect(formatColour(simulated, "hex")).not.toBe("#c82814");
    expect(Object.keys(simulateColourVisionSet(original))).toEqual([
      "protanopia",
      "deuteranopia",
      "tritanopia",
      "achromatopsia",
    ]);
  });
  it("turns achromatopsia output neutral", () => {
    const simulated = simulateColourVision("#ff8000", "achromatopsia");
    expect(simulated.coords[0]).toBeCloseTo(simulated.coords[1]!, 8);
    expect(simulated.coords[1]).toBeCloseTo(simulated.coords[2]!, 8);
  });
 });
 describe("palette construction and export", () => {
  it("builds useful hue harmonies", () => {
    expect(colourHarmony("oklch(60% .15 20)", "complementary")).toHaveLength(2);
    expect(colourHarmony("oklch(60% .15 20)", "analogous")).toHaveLength(3);
    expect(colourHarmony("oklch(60% .15 20)", "square")).toHaveLength(4);
  });
  it("builds deterministic tint, shade and tone scales", () => {
    expect(tints("#336699", 3)).toHaveLength(3);
    expect(shades("#336699", 3, { includeBase: true })).toHaveLength(4);
    expect(tones("#336699", 2, { includeEndpoint: true })).toHaveLength(2);
    expect(
      formatColour(tints("black", 1, { includeEndpoint: true })[0]!, "hex"),
    ).toBe("#ffffff");
  });
  it("parses named text, CSS variables, arrays and token JSON", () => {
    const text = parsePaletteList("Primary: #f8f5ee\n--accent: rgb(20 40 60)");
    expect(text.map((entry) => entry.name)).toEqual(["Primary", "accent"]);
    expect(parsePaletteList('["red", "blue"]')).toHaveLength(2);
    const tokens = parsePaletteList(
      '{"brand":{"$type":"color","$value":"#123456"}}',
    );
    expect(formatColour(tokens[0]!.colour, "hex")).toBe("#123456");
    const nested = parsePaletteList(
      '{"brand":{"light":{"$type":"color","$value":"#eee"},"dark":{"$value":"#111"}}}',
    );
    expect(nested.map((entry) => entry.name)).toEqual([
      "brand-light",
      "brand-dark",
    ]);
    expect(
      parsePaletteList(":root { --paper: #f8f5ee; --ink: #111; }"),
    ).toHaveLength(2);
  });
  it("normalises and de-duplicates portable token names", () => {
    expect(normaliseTokenName("  Crème brûlée / 100  ")).toBe(
      "creme-brulee-100",
    );
    const entries = parsePaletteList("Brand: red\nBrand: blue");
    expect(exportPalette(entries, "css", { prefix: "App" })).toContain(
      "--app-brand-2: #0000ff;",
    );
  });
  it("exports CSS, Sass, JSON, DTCG, Tailwind and CSV", () => {
    const entries = parsePaletteList("paper: #f8f5ee\nink: #111");
    expect(exportPalette(entries, "css")).toContain("--colour-paper: #f8f5ee;");
    expect(exportPalette(entries, "scss")).toContain("$colour-ink: #111111;");
    expect(JSON.parse(exportPalette(entries, "json"))).toEqual({
      paper: "#f8f5ee",
      ink: "#111111",
    });
    expect(JSON.parse(exportPalette(entries, "tokens")).paper).toEqual({
      $type: "color",
      $value: "#f8f5ee",
    });
    expect(exportPalette(entries, "tailwind")).toMatch(/^export default /);
    expect(exportPalette(entries, "csv")).toBe(
      "name,value\npaper,#f8f5ee\nink,#111111",
    );
  });
 });
@@ -0,0 +1,130 @@
 import fc from "fast-check";
 import { describe, expect, it } from "vitest";
 import { compositeLayers, compositeSourceOver } from "../../src/colour";
 import type { BlendMode } from "../../src/colour";
 describe("source-over compositing", () => {
  it("matches the canonical translucent-red-over-white result", () => {
    const result = compositeSourceOver("rgba(255, 0, 0, .5)", "white");
    expect(result.colour.coords).toEqual([1, 0.5, 0.5]);
    expect(result.colour.alpha).toBe(1);
    expect(result.hex).toBe("#ff8080");
  });
  it("composites an arbitrary RGBA reference with the source-over equation", () => {
    const result = compositeSourceOver(
      "rgba(0, 129, 255, .42)",
      "rgb(255, 255, 255)",
    );
    expect(result.colour.coords[0]).toBeCloseTo(0.58, 12);
    expect(result.colour.coords[1]).toBeCloseTo(0.7924705882352941, 12);
    expect(result.colour.coords[2]).toBe(1);
  });
  it("supports N layers and an explicit stack order", () => {
    const layers = [
      { colour: "white" },
      { colour: "rgba(255,0,0,.5)" },
      { colour: "rgba(0,0,255,.5)" },
    ];
    expect(compositeLayers(layers).hex).toBe("#8040bf");
    expect(
      compositeLayers([...layers].reverse(), { order: "top-to-bottom" }).hex,
    ).toBe("#8040bf");
  });
  it("offers visibly different sRGB and linear-light workflows", () => {
    const srgb = compositeSourceOver("rgba(255,0,0,.5)", "#00ff00", {
      space: "srgb",
    });
    const linear = compositeSourceOver("rgba(255,0,0,.5)", "#00ff00", {
      space: "linear-srgb",
    });
    expect(srgb.hex).toBe("#808000");
    expect(linear.hex).toBe("#bcbc00");
  });
  it("implements opacity and common blend modes", () => {
    expect(
      compositeSourceOver("#ff0000", "#808080", { blendMode: "multiply" }).hex,
    ).toBe("#800000");
    expect(
      compositeSourceOver("#ff0000", "#808080", { blendMode: "screen" }).hex,
    ).toBe("#ff8080");
    expect(compositeSourceOver("#ff0000", "#ffffff", { opacity: 0 }).hex).toBe(
      "#ffffff",
    );
  });
  it("keeps every exposed blend mode renderable", () => {
    const modes: BlendMode[] = [
      "normal",
      "multiply",
      "screen",
      "overlay",
      "darken",
      "lighten",
      "color-dodge",
      "color-burn",
      "hard-light",
      "soft-light",
      "difference",
      "exclusion",
      "hue",
      "saturation",
      "color",
      "luminosity",
    ];
    for (const blendMode of modes) {
      const result = compositeSourceOver("rgba(230,30,80,.7)", "#2878c8", {
        blendMode,
      });
      expect(result.colour.coords.every(Number.isFinite), blendMode).toBe(true);
      expect(result.hex, blendMode).toMatch(/^#[0-9a-f]{6}$/);
    }
  });
  it("keeps arbitrary composites bounded and alpha-correct", () => {
    fc.assert(
      fc.property(
        fc.tuple(
          fc.double({ min: 0, max: 1, noNaN: true }),
          fc.double({ min: 0, max: 1, noNaN: true }),
          fc.double({ min: 0, max: 1, noNaN: true }),
          fc.double({ min: 0, max: 1, noNaN: true }),
        ),
        fc.tuple(
          fc.double({ min: 0, max: 1, noNaN: true }),
          fc.double({ min: 0, max: 1, noNaN: true }),
          fc.double({ min: 0, max: 1, noNaN: true }),
          fc.double({ min: 0, max: 1, noNaN: true }),
        ),
        (foreground, background) => {
          const result = compositeSourceOver(
            {
              space: "srgb",
              coords: foreground.slice(0, 3) as [number, number, number],
              alpha: foreground[3],
            },
            {
              space: "srgb",
              coords: background.slice(0, 3) as [number, number, number],
              alpha: background[3],
            },
          ).colour;
          expect(
            result.coords.every((channel) => channel >= 0 && channel <= 1),
          ).toBe(true);
          expect(result.alpha).toBeGreaterThanOrEqual(0);
          expect(result.alpha).toBeLessThanOrEqual(1);
          expect(result.alpha).toBeCloseTo(
            foreground[3] + background[3] * (1 - foreground[3]),
            12,
          );
        },
      ),
      { numRuns: 100 },
    );
  });
 });
@@ -0,0 +1,142 @@
 import { describe, expect, it } from "vitest";
 import {
  contrastRatio,
  contrastReport,
  formatColour,
  gamutReport,
  interpolateColourStops,
  interpolateStops,
  mapToGamut,
  nearestPassingColour,
  relativeLuminance,
 } from "../../src/colour";
 describe("multi-stop interpolation", () => {
  it("interpolates across positioned stops", () => {
    const stops = [
      { colour: "#ff0000", position: 0 },
      { colour: "#00ff00", position: 0.5 },
      { colour: "#0000ff", position: 1 },
    ];
    expect(
      formatColour(
        interpolateColourStops(stops, 0.25, { space: "srgb" }),
        "hex",
      ),
    ).toBe("#808000");
    expect(
      formatColour(
        interpolateColourStops(stops, 0.75, { space: "srgb" }),
        "hex",
      ),
    ).toBe("#008080");
  });
  it("distributes omitted positions and includes exact endpoints", () => {
    const steps = interpolateStops(
      [{ colour: "black" }, { colour: "red" }, { colour: "white" }],
      5,
      {
        space: "srgb",
      },
    );
    expect(steps.map((step) => step.hex)).toEqual([
      "#000000",
      "#800000",
      "#ff0000",
      "#ff8080",
      "#ffffff",
    ]);
    expect(steps.map((step) => step.position)).toEqual([0, 0.25, 0.5, 0.75, 1]);
  });
  it("takes the shorter hue path across zero", () => {
    const middle = interpolateColourStops(
      [{ colour: "hsl(350 100% 50%)" }, { colour: "hsl(10 100% 50%)" }],
      0.5,
      { space: "hsl", hue: "shorter" },
    );
    expect(formatColour(middle, "hex")).toBe("#ff0000");
  });
  it("supports deterministic easing", () => {
    const linear = interpolateColourStops(
      [{ colour: "black" }, { colour: "white" }],
      0.5,
      { space: "srgb" },
    );
    const eased = interpolateColourStops(
      [{ colour: "black" }, { colour: "white" }],
      0.5,
      {
        space: "srgb",
        easing: "ease-in",
      },
    );
    expect(linear.coords[0]).toBeCloseTo(0.5);
    expect(eased.coords[0]).toBeCloseTo(0.25);
  });
  it("premultiplies alpha by default to avoid transparent colour fringes", () => {
    const premultiplied = interpolateColourStops(
      [{ colour: "rgba(255, 0, 0, 0)" }, { colour: "rgba(0, 0, 255, 1)" }],
      0.5,
      { space: "srgb" },
    );
    const straight = interpolateColourStops(
      [{ colour: "rgba(255, 0, 0, 0)" }, { colour: "rgba(0, 0, 255, 1)" }],
      0.5,
      { space: "srgb", premultiplied: false },
    );
    expect(premultiplied.alpha).toBeCloseTo(0.5);
    expect(premultiplied.coords).toEqual([0, 0, 1]);
    expect(straight.coords).toEqual([0.5, 0, 0.5]);
  });
 });
 describe("gamut and accessibility", () => {
  it("reports and maps wide-gamut colours", () => {
    const report = gamutReport("color(display-p3 1 0 0)");
    expect(report.spaces.find((space) => space.space === "srgb")?.inGamut).toBe(
      false,
    );
    expect(report.spaces.find((space) => space.space === "p3")?.inGamut).toBe(
      true,
    );
    expect(
      report.spaces.find((space) => space.space === "p3")?.mappedCss,
    ).toMatch(/^color\(display-p3 /);
    const mapped = mapToGamut("color(display-p3 1 0 0)");
    expect(
      mapped.coords.every((channel) => channel >= -1e-9 && channel <= 1 + 1e-9),
    ).toBe(true);
  });
  it("uses WCAG relative luminance and contrast thresholds", () => {
    expect(relativeLuminance("black")).toBe(0);
    expect(relativeLuminance("white")).toBe(1);
    expect(contrastRatio("black", "white")).toBe(21);
    const report = contrastReport("#777", "white");
    expect(report.ratio).toBeCloseTo(4.478089, 5);
    expect(report.passes.aaNormal).toBe(false);
    expect(report.passes.aaLarge).toBe(true);
  });
  it("flattens alpha against the visible background", () => {
    expect(contrastRatio("rgba(0,0,0,.5)", "white")).toBeCloseTo(3.976653, 5);
    expect(
      contrastReport("black", "rgba(255,255,255,.5)", { canvas: "black" })
        .ratio,
    ).toBeCloseTo(5.280823, 4);
  });
  it("finds a nearby foreground that passes a requested target", () => {
    const suggestion = nearestPassingColour("#777", "white", 4.5);
    expect(suggestion).not.toBeNull();
    expect(suggestion?.direction).toBe("darker");
    expect(suggestion?.ratio).toBeGreaterThanOrEqual(4.5);
    expect(suggestion?.deltaEOK).toBeLessThan(0.02);
  });
 });
@@ -0,0 +1,106 @@
 import fc from "fast-check";
 import { describe, expect, it } from "vitest";
 import {
  conversionRows,
  formatColour,
  parseColour,
  parseColourList,
  toSrgbPreview,
  tryParseColour,
 } from "../../src/colour";
 describe("colour parsing and conversion", () => {
  it("converts the RapidTables reference colour", () => {
    const colour = parseColour("#f8f5ee");
    expect(colour.space).toBe("srgb");
    expect(colour.coords).toEqual([248 / 255, 245 / 255, 238 / 255]);
    expect(formatColour(colour, "hex")).toBe("#f8f5ee");
    expect(formatColour(colour, "rgb")).toBe("rgb(248, 245, 238)");
    expect(formatColour(colour, "hsl")).toBe("hsl(42 41.6667% 95.2941%)");
  });
  it("accepts CSS Color 4, named, bare hex and numeric RGB input", () => {
    expect(formatColour("rebeccapurple", "hex")).toBe("#663399");
    expect(formatColour("f8f5ee", "hex")).toBe("#f8f5ee");
    expect(formatColour("0xff000080", "hex8")).toBe("#ff000080");
    expect(formatColour("248, 245, 238", "hex")).toBe("#f8f5ee");
    const p3 = parseColour("color(display-p3 1 0.2 0.1 / 75%)");
    expect(p3.space).toBe("p3");
    expect(p3.alpha).toBeCloseTo(0.75);
  });
  it("parses custom HSV/HSB with angles and alpha", () => {
    expect(formatColour("hsv(120 50% 60% / 25%)", "rgba")).toBe(
      "rgba(77, 153, 77, 0.25)",
    );
    expect(formatColour("hsb(.333333turn, .5, .6)", "hex")).toBe("#4d994d");
    expect(parseColour("hsv(-30deg 100% 100%)").coords[0]).toBe(330);
  });
  it("parses custom CMYK and converts it deterministically", () => {
    expect(formatColour("cmyk(0% 100% 100% 0% / .5)", "hex8")).toBe(
      "#ff000080",
    );
    expect(formatColour("cmyk(100%, 0%, 100%, 25%)", "rgb")).toBe(
      "rgb(0, 191, 0)",
    );
    expect(formatColour("#000", "cmyk")).toBe("cmyk(0% 0% 0% 100%)");
  });
  it("returns structured failures without throwing", () => {
    expect(tryParseColour("")).toMatchObject({
      ok: false,
      error: { code: "empty" },
    });
    expect(tryParseColour("hsv(20 200% 20%)")).toMatchObject({
      ok: false,
      error: { code: "out-of-range" },
    });
    expect(tryParseColour("definitely-not-a-colour").ok).toBe(false);
  });
  it("splits lists only at top-level delimiters", () => {
    const colours = parseColourList("rgb(1, 2, 3), hsl(20 30% 40%);\n#fff");
    expect(colours).toHaveLength(3);
    expect(formatColour(colours[0]!, "rgb")).toBe("rgb(1, 2, 3)");
    expect(parseColourList('["#f00", "#0f0"]')).toHaveLength(2);
  });
  it("offers copy-ready conversion rows and a safe preview", () => {
    const rows = conversionRows("#f8f5ee", ["hex", "rgb", "oklch"]);
    expect(rows.map((row) => row.label)).toEqual(["HEX", "RGB", "OKLCH"]);
    expect(rows[0]?.copyValue).toBe("#f8f5ee");
    const preview = toSrgbPreview("color(display-p3 1 0 0)");
    expect(preview.wasMapped).toBe(true);
    expect(preview.css).toMatch(/^rgb\(/);
    expect(preview.rgb.every((channel) => channel >= 0 && channel <= 1)).toBe(
      true,
    );
  });
  it("round-trips arbitrary 8-bit RGB colours through HEX", () => {
    fc.assert(
      fc.property(
        fc.integer({ min: 0, max: 255 }),
        fc.integer({ min: 0, max: 255 }),
        fc.integer({ min: 0, max: 255 }),
        (red, green, blue) => {
          const value = {
            space: "srgb",
            coords: [red / 255, green / 255, blue / 255] as [
              number,
              number,
              number,
            ],
            alpha: 1,
          };
          expect(parseColour(formatColour(value, "hex")).coords).toEqual(
            value.coords,
          );
        },
      ),
      { numRuns: 200 },
    );
  });
 });
@@ -0,0 +1,70 @@
 import { fireEvent, render, screen, within } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { CompositeLab } from "../../src/components/CompositeLab";
 import { ConverterLab } from "../../src/components/ConverterLab";
 import { PickerLab } from "../../src/components/PickerLab";
 import { Workbench } from "../../src/components/Workbench";
 describe("colour workbench", () => {
  beforeEach(() => {
    localStorage.clear();
    history.replaceState(null, "", "/");
  });
  it("exposes all seven workspaces as accessible tabs", () => {
    render(<Workbench />);
    const tabs = screen.getAllByRole("tab");
    expect(tabs).toHaveLength(7);
    expect(tabs[0]).toHaveAttribute("aria-selected", "true");
    expect(
      screen.getByRole("heading", { name: "Convert colours" }),
    ).toBeVisible();
  });
  it("supports keyboard navigation between workspaces", async () => {
    render(<Workbench />);
    const convert = screen.getByRole("tab", { name: /Convert/ });
    convert.focus();
    await userEvent.keyboard("{ArrowRight}");
    expect(screen.getByRole("tab", { name: /Composite/ })).toHaveAttribute(
      "aria-selected",
      "true",
    );
    expect(
      screen.getByRole("heading", { name: "Composite translucent colours" }),
    ).toBeVisible();
  });
 });
 describe("interactive colour labs", () => {
  it("keeps the last valid conversion visible while an input is incomplete", async () => {
    render(<ConverterLab onAddColour={vi.fn()} />);
    const source = screen.getByLabelText("Colour");
    await userEvent.clear(source);
    await userEvent.type(source, "oklch(");
    expect(source).toHaveAttribute("aria-invalid", "true");
    expect(screen.getByText(/Keeping the last valid conversion/)).toBeVisible();
    expect(screen.getByText("HEX + alpha")).toBeVisible();
  });
  it("produces an opaque composite over the enabled matte", () => {
    render(<CompositeLab onAddColour={vi.fn()} />);
    const result = screen.getByText("Result").closest("aside");
    expect(result).not.toBeNull();
    expect(within(result!).getByText(/^#[0-9a-f]{6}$/i)).toBeVisible();
    expect(screen.getByText(/Produces an opaque RGB result/)).toBeVisible();
  });
  it("keeps the exact picker field in sync with visual controls", () => {
    render(<PickerLab onAddColour={vi.fn()} />);
    const hue = screen.getByLabelText(/Hue ·/);
    fireEvent.change(hue, { target: { value: "0" } });
    expect(screen.getByLabelText("Exact CSS colour")).toHaveValue("#d14f4f");
    expect(screen.getByText("#d14f4f")).toBeVisible();
  });
 });
@@ -0,0 +1,87 @@
 import { describe, expect, it } from "vitest";
 import {
  getBoundedSampleRegion,
  mapClientPointToPixel,
  validateImageDimensions,
  validateImageFile,
 } from "../../src/palette/bounds";
 import type { ImageLimits } from "../../src/palette/types";
 const limits: ImageLimits = {
  maxBytes: 1_000,
  maxPixels: 100,
  maxDimension: 20,
  acceptedMimeTypes: ["image/png"],
 };
 describe("local image bounds", () => {
  it("rejects empty, oversized, and unsupported files", () => {
    expect(
      validateImageFile(
        { name: "empty.png", size: 0, type: "image/png" },
        limits,
      ).valid,
    ).toBe(false);
    expect(
      validateImageFile(
        { name: "large.png", size: 1_001, type: "image/png" },
        limits,
      ).valid,
    ).toBe(false);
    expect(
      validateImageFile(
        { name: "vector.svg", size: 10, type: "image/svg+xml" },
        limits,
      ).valid,
    ).toBe(false);
  });
  it("accepts a bounded raster file", () => {
    expect(
      validateImageFile(
        { name: "pixel.png", size: 999, type: "IMAGE/PNG" },
        limits,
      ),
    ).toEqual({
      valid: true,
    });
    expect(
      validateImageFile({ name: "pixel.png", size: 999, type: "" }, limits)
        .valid,
    ).toBe(true);
  });
  it("checks decoded dimensions and pixel area", () => {
    expect(validateImageDimensions(10, 10, limits).valid).toBe(true);
    expect(validateImageDimensions(21, 2, limits).valid).toBe(false);
    expect(validateImageDimensions(11, 10, limits).valid).toBe(false);
    expect(validateImageDimensions(Number.NaN, 10, limits).valid).toBe(false);
  });
  it("maps CSS-scaled canvas coordinates to bounded image pixels", () => {
    const rect = { left: 100, top: 50, width: 200, height: 100 };
    expect(mapClientPointToPixel(200, 100, rect, 1_000, 500)).toEqual({
      x: 500,
      y: 250,
    });
    expect(mapClientPointToPixel(500, -20, rect, 1_000, 500)).toEqual({
      x: 999,
      y: 0,
    });
    expect(
      mapClientPointToPixel(200, 100, { ...rect, width: 0 }, 1_000, 500),
    ).toBeNull();
  });
  it("clips sampling regions at image edges", () => {
    expect(getBoundedSampleRegion(0, 0, 2, 10, 8)).toEqual({
      left: 0,
      top: 0,
      width: 3,
      height: 3,
      centerX: 0,
      centerY: 0,
    });
    expect(getBoundedSampleRegion(Number.NaN, 0, 2, 10, 8)).toBeNull();
  });
 });
@@ -0,0 +1,66 @@
 import { afterEach, describe, expect, it, vi } from "vitest";
 import { decodeLocalImage } from "../../src/palette/decode";
 const nativeUrl = globalThis.URL;
 afterEach(() => {
  vi.unstubAllGlobals();
 });
 const installImageElementDecoder = (loadImmediately: boolean) => {
  const createObjectURL = vi.fn(() => "blob:local-image");
  const revokeObjectURL = vi.fn();
  class MockUrl extends nativeUrl {
    static createObjectURL = createObjectURL;
    static revokeObjectURL = revokeObjectURL;
  }
  class MockImage {
    decoding = "auto";
    naturalWidth = 320;
    naturalHeight = 180;
    onload: (() => void) | null = null;
    onerror: (() => void) | null = null;
    private source = "";
    set src(value: string) {
      this.source = value;
      if (value && loadImmediately) queueMicrotask(() => this.onload?.());
    }
    get src(): string {
      return this.source;
    }
  }
  vi.stubGlobal("URL", MockUrl);
  vi.stubGlobal("Image", MockImage);
  vi.stubGlobal("createImageBitmap", undefined);
  return { createObjectURL, revokeObjectURL };
 };
 describe("local image decoding", () => {
  it("revokes its object URL as soon as the image has decoded", async () => {
    const spies = installImageElementDecoder(true);
    const image = await decodeLocalImage(
      new File(["image"], "sample.png", { type: "image/png" }),
    );
    expect(image).toMatchObject({ width: 320, height: 180 });
    expect(spies.createObjectURL).toHaveBeenCalledOnce();
    expect(spies.revokeObjectURL).toHaveBeenCalledWith("blob:local-image");
    image.dispose();
  });
  it("revokes its object URL when decoding is cancelled", async () => {
    const spies = installImageElementDecoder(false);
    const controller = new AbortController();
    const decoding = decodeLocalImage(
      new File(["image"], "sample.png", { type: "image/png" }),
      controller.signal,
    );
    controller.abort();
    await expect(decoding).rejects.toMatchObject({ name: "AbortError" });
    expect(spies.revokeObjectURL).toHaveBeenCalledWith("blob:local-image");
  });
 });
@@ -0,0 +1,88 @@
 import { describe, expect, it, vi } from "vitest";
 import { extractPalette } from "../../src/palette/extract";
 import { extractPaletteSafely } from "../../src/palette/worker-client";
 const makePixels = (
  colours: readonly (readonly [number, number, number, number])[],
 ) => ({
  width: colours.length,
  height: 1,
  data: new Uint8ClampedArray(colours.flat()),
 });
 describe("deterministic Oklab palette extraction", () => {
  it("returns dominant colours in coverage order", () => {
    const input = makePixels([
      [255, 0, 0, 255],
      [255, 0, 0, 255],
      [255, 0, 0, 255],
      [0, 0, 255, 255],
    ]);
    const palette = extractPalette(input, { count: 2 });
    expect(palette.map((colour) => colour.hex)).toEqual(["#FF0000", "#0000FF"]);
    expect(palette[0]?.coverage).toBeCloseTo(0.75, 8);
    expect(palette[1]?.coverage).toBeCloseTo(0.25, 8);
  });
  it("produces byte-for-byte stable results for repeated runs", () => {
    const input = makePixels([
      [248, 245, 238, 255],
      [20, 80, 180, 255],
      [245, 140, 20, 255],
      [248, 245, 238, 255],
      [25, 85, 175, 220],
      [240, 145, 25, 255],
    ]);
    const first = extractPalette(input, { count: 3 });
    const second = extractPalette(input, { count: 3 });
    expect(second).toEqual(first);
  });
  it("ignores fully transparent pixels and respects the alpha threshold", () => {
    const input = makePixels([
      [255, 0, 255, 0],
      [255, 0, 0, 15],
      [0, 255, 0, 255],
      [0, 0, 255, 255],
    ]);
    const palette = extractPalette(input, { count: 3, minimumAlpha: 16 });
    expect(palette.map((colour) => colour.hex)).toEqual(["#0000FF", "#00FF00"]);
    expect(
      palette.reduce((sum, colour) => sum + colour.coverage, 0),
    ).toBeCloseTo(1, 8);
  });
  it("handles a fully transparent image without inventing colours", () => {
    expect(extractPalette(makePixels([[10, 20, 30, 0]]), { count: 6 })).toEqual(
      [],
    );
  });
  it("rejects malformed pixel buffers", () => {
    expect(() =>
      extractPalette(
        { width: 2, height: 2, data: new Uint8ClampedArray(4) },
        { count: 2 },
      ),
    ).toThrow("Invalid pixel buffer");
  });
  it("falls back safely when Web Workers are unavailable", async () => {
    const input = makePixels([
      [255, 0, 0, 255],
      [0, 0, 255, 255],
    ]);
    vi.stubGlobal("Worker", undefined);
    try {
      await expect(
        extractPaletteSafely(input, { count: 2 }),
      ).resolves.toHaveLength(2);
    } finally {
      vi.unstubAllGlobals();
    }
  });
 });
@@ -0,0 +1,95 @@
 import { describe, expect, it } from "vitest";
 import { samplePixels } from "../../src/palette/sample";
 const pixels = (
  width: number,
  colours: readonly (readonly [number, number, number, number])[],
 ) => ({
  width,
  height: colours.length / width,
  data: new Uint8ClampedArray(colours.flat()),
 });
 describe("pixel sampling", () => {
  it("returns the exact pixel for a zero-radius sample", () => {
    const result = samplePixels(
      pixels(2, [
        [12, 34, 56, 255],
        [200, 100, 50, 128],
      ]),
      1,
      0,
      0,
      "average",
    );
    expect(result).toMatchObject({
      r: 200,
      g: 100,
      b: 50,
      a: 128,
      hex: "#C8643280",
      pixelCount: 1,
    });
  });
  it("uses a circular neighbourhood and alpha-weighted RGB average", () => {
    const data = pixels(3, [
      [0, 0, 0, 0],
      [255, 0, 0, 255],
      [0, 0, 0, 0],
      [0, 255, 0, 255],
      [0, 0, 255, 0],
      [0, 0, 0, 0],
      [0, 0, 0, 0],
      [255, 255, 255, 255],
      [0, 0, 0, 0],
    ]);
    const result = samplePixels(data, 1, 1, 1, "average");
    expect(result).toMatchObject({
      r: 170,
      g: 170,
      b: 85,
      a: 153,
      pixelCount: 5,
    });
  });
  it("calculates channel medians from visible samples", () => {
    const result = samplePixels(
      pixels(3, [
        [10, 90, 200, 255],
        [200, 50, 10, 128],
        [100, 10, 90, 0],
      ]),
      1,
      0,
      1,
      "median",
    );
    expect(result).toMatchObject({
      r: 105,
      g: 70,
      b: 105,
      a: 128,
      pixelCount: 3,
    });
  });
  it("rejects invalid coordinates and truncated buffers", () => {
    expect(
      samplePixels(pixels(1, [[1, 2, 3, 4]]), 1, 0, 0, "average"),
    ).toBeNull();
    expect(
      samplePixels(
        { width: 2, height: 2, data: new Uint8ClampedArray(4) },
        0,
        0,
        0,
        "average",
      ),
    ).toBeNull();
  });
 });
@@ -0,0 +1,27 @@
 {
  "compilerOptions": {
    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo",
    "target": "ES2023",
    "lib": ["ES2023", "DOM", "DOM.Iterable"],
    "module": "ESNext",
    "types": ["vite/client"],
    "allowArbitraryExtensions": true,
    "skipLibCheck": true,
    "moduleResolution": "Bundler",
    "allowImportingTsExtensions": true,
    "verbatimModuleSyntax": true,
    "moduleDetection": "force",
    "noEmit": true,
    "jsx": "react-jsx",
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "erasableSyntaxOnly": true,
    "noFallthroughCasesInSwitch": true,
    "strict": true,
    "noUncheckedIndexedAccess": true,
    "useDefineForClassFields": true,
    "resolveJsonModule": true,
    "isolatedModules": true
  },
  "include": ["src", "tests"]
 }
@@ -0,0 +1,7 @@
 {
  "files": [],
  "references": [
    { "path": "./tsconfig.app.json" },
    { "path": "./tsconfig.node.json" }
  ]
 }
@@ -0,0 +1,24 @@
 {
  "compilerOptions": {
    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.node.tsbuildinfo",
    "target": "ES2023",
    "lib": ["ES2023"],
    "module": "ESNext",
    "types": ["node"],
    "skipLibCheck": true,
    "moduleResolution": "Bundler",
    "allowImportingTsExtensions": true,
    "verbatimModuleSyntax": true,
    "moduleDetection": "force",
    "noEmit": true,
    "strict": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true
  },
  "include": [
    "vite.config.ts",
    "playwright.config.ts",
    "eslint.config.mjs",
    "scripts/**/*.mjs"
  ]
 }
@@ -0,0 +1,16 @@
 /// <reference types="vitest/config" />
 import { defineConfig } from "vite";
 import react from "@vitejs/plugin-react";
 export default defineConfig({
  base: "./",
  plugins: [react()],
  test: {
    environment: "jsdom",
    setupFiles: "./src/test/setup.ts",
    css: true,
    maxWorkers: 2,
    restoreMocks: true,
    exclude: ["tests/browser/**", "node_modules/**", "dist/**"],
  },
 });
		`@@ -0,0 +1 @@`
							`@add-ideas:registry=https://git.add-ideas.de/api/packages/lotobo/npm/`