Adopt shared WebUI layout primitives

webui/src/styles/forms.css

@@ -145,12 +145,6 @@
   justify-content: flex-end;
 }
 
-.form-definition-grid {
-  display: grid;
-  grid-template-columns: repeat(2, minmax(0, 1fr));
-  gap: 12px 16px;
-}
-
 .form-definition-wide {
   grid-column: 1 / -1;
 }
@@ -229,13 +223,6 @@
   grid-column: 2 / -1;
 }
 
-.form-field-constraints,
-.form-field-condition {
-  display: grid;
-  grid-template-columns: repeat(3, minmax(0, 1fr));
-  gap: 9px;
-}
-
 .form-composition-section {
   display: flex;
   flex-direction: column;
@@ -302,9 +289,7 @@
 }
 
 .form-preview-grid {
-  display: grid;
-  grid-template-columns: repeat(2, minmax(0, 1fr));
-  gap: 18px;
+  min-width: 0;
 }
 
 .form-preview-grid > div {
@@ -374,14 +359,10 @@
 }
 
 @media (max-width: 620px) {
-  .form-definition-grid,
-  .form-field-constraints,
-  .form-field-condition,
   .form-page-editor-heading,
   .form-section-editor,
   .form-localization-editor,
-  .form-localization-fields,
-  .form-preview-grid {
+  .form-localization-fields {
     grid-template-columns: 1fr;
   }