[eric] ui: the input readability fix touches colour only, not the geometry of 74 controls (ENG-281)

frontend/src/shared/styles/inputOverrides.test.ts

@@ -24,9 +24,19 @@ const light = {
 } as unknown as ClaudeTokens;
 
 for (const [name, tokens] of [['dark', dark], ['light', light]] as const) {
-  test(`${name}: typed text is never the same colour as the field it sits on`, () => {
+  test(`${name}: typed text is never the same colour as the surface it sits on`, () => {
     const root = inputStyleOverrides(tokens).root as Record<string, string>;
-    assert.notEqual(root.color, root.backgroundColor, 'text and field background are identical');
+    const surface = (tokens as unknown as { bg: { surface: string } }).bg.surface;
+    assert.notEqual(root.color, surface, 'text colour equals the surface behind the field');
+  });
+
+  test(`${name}: the override changes ONLY colour, never geometry or fill`, () => {
+    // Regression guard on my own scope creep: an earlier version restyled 74 controls to fix a
+    // contrast bug. Anything here that is not a colour is out of bounds.
+    const root = inputStyleOverrides(tokens).root as Record<string, unknown>;
+    for (const banned of ['borderRadius', 'backgroundColor', 'border', 'padding', 'height', 'fontSize']) {
+      assert.equal(root[banned], undefined, `override sets ${banned}, which is not a readability fix`);
+    }
   });
 
   test(`${name}: the inner input and textarea inherit the readable colour, not MUI's`, () => {
@@ -43,6 +53,7 @@ for (const [name, tokens] of [['dark', dark], ['light', light]] as const) {
 }
 
 test('the override actually sets a colour at all, so a future empty return fails here', () => {
-  const root = inputStyleOverrides(dark).root as Record<string, string>;
-  assert.ok(root.color && root.backgroundColor, 'override returned nothing to inherit');
+  const root = inputStyleOverrides(dark).root as Record<string, unknown>;
+  assert.ok(root.color, 'override returned nothing to inherit');
+  assert.ok(root['& input, & textarea'], 'inner input rule missing');
 });

frontend/src/shared/styles/inputOverrides.ts

@@ -1,24 +1,24 @@
 import type { ClaudeTokens } from './claudeTokens';
 
-// A bare <TextField> renders with MUI's own palette, not ours. On a dark surface that is black text
-// on a black field: you cannot see what you are typing (ENG-281, hit on the question flow's
-// "Other..." box). Fixing the one call site would leave every future bare field able to do it again,
-// so the colours are pinned at the theme and every input in the app inherits them.
+// A bare <TextField> renders its text with MUI's palette, not ours. On a dark surface that is black
+// text on a black field: you cannot see what you are typing (ENG-281, hit on the question flow's
+// "Other..." box). Pinned at the theme so every input inherits it and no future bare field can
+// reintroduce the bug.
+//
+// Deliberately COLOUR ONLY. An earlier version of this also set borderRadius, backgroundColor and
+// the fieldset border colours, which changed the appearance of all 38 TextFields and 36 Selects in
+// the app (Select renders through MuiOutlinedInput too) to fix a problem that was only ever about
+// text contrast. Geometry and fill are left exactly as they were: the blast radius of a readability
+// fix should be readability.
 
 export function inputStyleOverrides(c: ClaudeTokens): Record<string, object> {
   return {
     root: {
       color: c.text.primary,
-      backgroundColor: c.bg.surface,
-      borderRadius: 10,
       '& input, & textarea': { color: c.text.primary },
-      // Placeholders need their own rule: MUI paints them via opacity on the inherited colour, which
+      // Placeholders need their own rule: MUI dims them with opacity on the inherited colour, which
       // lands invisible when the inherited colour was already wrong.
       '& input::placeholder, & textarea::placeholder': { color: c.text.tertiary, opacity: 1 },
-      '& fieldset': { borderColor: c.border.medium },
-      '&:hover fieldset': { borderColor: c.border.strong },
-      '&.Mui-focused fieldset': { borderColor: c.accent.primary },
-      '&.Mui-disabled': { color: c.text.ghost },
     },
   };
 }