[eric] chat: the answer box is a raised surface, not a well dug into the card (ENG-419)

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01U6zrBsUCNzpMBnov3rTVYV

frontend/src/app/pages/AgentChat/tool-ui/AskQuestionCard.tsx

@@ -100,8 +100,10 @@ const AskQuestionCard: React.FC<QuestionFormProps> = (props) => {
           }}
         />
       )}
+      {/* elevated, not secondary: this is the box you TYPE IN, and on dark, secondary (#1f1e1b) sits
+          below the surface around it, so the one interactive thing in the widget read as a well. */}
       {pendingOther.length > 0 && (
-        <Box sx={{ bgcolor: c.bg.secondary, borderRadius: 2.5, p: 2, display: 'flex', flexDirection: 'column', gap: 1.25 }}>
+        <Box sx={{ bgcolor: c.bg.elevated, borderRadius: 2.5, p: 2, display: 'flex', flexDirection: 'column', gap: 1.25 }}>
           {pendingOther.map((stepId) => {
             const idx = Number(stepId.slice(2));
             return (

frontend/src/app/pages/AgentChat/tool-ui/QuestionForm.tsx

@@ -113,8 +113,10 @@ const QuestionForm: React.FC<QuestionFormProps> = ({ request, onApprove, onDeny,
   return (
     <Box
       sx={{
-        // Tint carries the container; the accent icon + title are the identity cue.
-        bgcolor: c.bg.secondary,
+        // Tint carries the container; the accent icon + title are the identity cue. Elevated, not
+        // secondary: this is an input surface, and on the dark palette secondary sits BELOW the
+        // surface it lands on, which reads as a well rather than something you type into.
+        bgcolor: c.bg.elevated,
         borderRadius: compact ? 2 : 2.5,
         p: compact ? 1.5 : 2,
         mx: compact ? 0 : 2,

frontend/src/app/pages/AgentChat/tool-ui/askBoxTone.test.ts

@@ -0,0 +1,54 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { darkTokens, lightTokens } from '@/shared/styles/claudeTokens';
+
+// The box you type an answer into used to be painted `bg.secondary`, which on the DARK palette sits
+// BELOW the surface it lands on (#1f1e1b against #262624). Text contrast was never the problem
+// (15.8:1); the tone was, and the one interactive element in the widget read as a recessed well.
+//
+// Asserted as a PROPERTY of the tokens, not as "the file says elevated": a palette edit that
+// re-inverts the relationship has to fail here, which naming the token would not catch.
+
+function luminance(hex: string): number {
+  const h = hex.replace('#', '');
+  const ch = [0, 2, 4].map((i) => parseInt(h.slice(i, i + 2), 16) / 255);
+  const lin = ch.map((c) => (c <= 0.03928 ? c / 12.92 : ((c + 0.055) / 1.055) ** 2.4));
+  return 0.2126 * lin[0] + 0.7152 * lin[1] + 0.0722 * lin[2];
+}
+
+function contrast(a: string, b: string): number {
+  const [hi, lo] = [luminance(a), luminance(b)].sort((x, y) => y - x);
+  return (hi + 0.05) / (lo + 0.05);
+}
+
+test('on dark, an input surface is never darker than the surface it sits on', () => {
+  assert.ok(
+    luminance(darkTokens.bg.elevated) > luminance(darkTokens.bg.surface),
+    'bg.elevated must read as raised on dark, or the answer box is a well again',
+  );
+  assert.ok(
+    luminance(darkTokens.bg.secondary) < luminance(darkTokens.bg.surface),
+    'this pins WHY secondary was wrong here; if it ever rises above surface, revisit the choice',
+  );
+});
+
+test('on light, the step is gentler than the one it replaced', () => {
+  // Honest scope: this holds on LIGHT (0.053 vs 0.098) and NOT on dark, where elevated is a bigger
+  // step than secondary was (0.0101 vs 0.0063) in the opposite direction. Direction is the fix on
+  // dark; softness is the bonus on light. An earlier version of this test claimed both palettes and
+  // was wrong, which is the whole reason it asserts numbers instead of a token name.
+  const wasStep = Math.abs(luminance(lightTokens.bg.secondary) - luminance(lightTokens.bg.surface));
+  const nowStep = Math.abs(luminance(lightTokens.bg.elevated) - luminance(lightTokens.bg.surface));
+  assert.ok(nowStep < wasStep, `light tone step got harsher: ${nowStep} >= ${wasStep}`);
+});
+
+test('on light it still reads as a distinct panel, not an invisible one', () => {
+  // The other direction of the same trade: soften it too far and the box stops being a box.
+  const step = Math.abs(luminance(lightTokens.bg.elevated) - luminance(lightTokens.bg.surface));
+  assert.ok(step > 0.02, `the panel vanished into the surface: step ${step}`);
+});
+
+test('text stays comfortably readable on it, which was never the bug but must not become one', () => {
+  assert.ok(contrast(darkTokens.bg.elevated, darkTokens.text.primary) >= 7);
+  assert.ok(contrast(lightTokens.bg.elevated, lightTokens.text.primary) >= 7);
+});