Floating dismissable alert - initial commit

src/styles/components.css

@@ -704,6 +704,19 @@
   flex: 1 1 auto;
 }
 
+.alert-floating {
+  position: fixed;
+  top: 131px;
+  left: 50%;
+  z-index: 1200;
+  width: min(640px, calc(100vw - 32px));
+  margin: 0;
+  transform: translateX(-50%);
+  border: 1px solid rgba(15, 23, 42, 0.14);
+  border-radius: 12px;
+  box-shadow: 0 16px 38px rgba(15, 23, 42, 0.2);
+}
+
 .alert-dismiss {
   border: 0;
   background: transparent;

src/styles/file-manager.css

@@ -8,20 +8,6 @@
   overflow: hidden;
 }
 
-.file-manager-alerts {
-  position: absolute;
-  top: 14px;
-  left: 18px;
-  right: 18px;
-  z-index: 40;
-  pointer-events: none;
-}
-
-.file-manager-alerts .alert {
-  pointer-events: auto;
-  box-shadow: var(--shadow-popover);
-}
-
 .file-manager-toolbar {
   display: flex;
   align-items: center;
@@ -487,13 +473,27 @@
   background: var(--panel-soft);
   color: var(--muted);
   text-align: center;
+  cursor: pointer;
+  transition: border-color .16s ease, background .16s ease, box-shadow .16s ease;
 }
 
+.file-upload-drop-zone:hover,
+.file-upload-drop-zone:focus-visible,
 .file-upload-drop-zone.is-active {
   border-color: #0d6efd;
   background: rgba(13, 110, 253, .08);
 }
 
+.file-upload-drop-zone:focus-visible {
+  outline: none;
+  box-shadow: 0 0 0 3px rgba(13, 110, 253, .18);
+}
+
+.file-upload-drop-zone[aria-disabled="true"] {
+  cursor: not-allowed;
+  opacity: .65;
+}
+
 .field-error {
   color: var(--danger-text);
   font-weight: 700;