feat: Added @keyframes pageEnter (opacity 0→1, translateY 8→0, 250ms ea…

- "frontend/src/App.css"

GSD-Task: S03/T02

.gsd/milestones/M010/slices/S03/S03-PLAN.md

@@ -22,7 +22,7 @@ Steps:
   - Estimate: 30m
   - Files: frontend/src/utils/catSlug.ts, frontend/src/pages/TopicsBrowse.tsx, frontend/src/pages/SubTopicPage.tsx, frontend/src/pages/SearchResults.tsx, frontend/src/App.css
   - Verify: cd frontend && npx tsc --noEmit && npm run build
-- [ ] **T02: Add CSS page-enter fade-in transitions to all pages** — Add a subtle CSS-only fade-in animation that triggers when page components mount. No libraries needed — a @keyframes animation applied to page wrapper elements.
+- [x] **T02: Added @keyframes pageEnter (opacity 0→1, translateY 8→0, 250ms ease-out) applied to all 7 public page wrapper classes via CSS selector list** — Add a subtle CSS-only fade-in animation that triggers when page components mount. No libraries needed — a @keyframes animation applied to page wrapper elements.
 
 Steps:
 1. In `frontend/src/App.css`, add a `@keyframes pageEnter` animation: opacity 0→1 and translateY(8px→0) over 250ms ease-out.

.gsd/milestones/M010/slices/S03/tasks/T01-VERIFY.json

@@ -0,0 +1,30 @@
+{
+  "schemaVersion": 1,
+  "taskId": "T01",
+  "unitId": "M010/S03/T01",
+  "timestamp": 1774938366406,
+  "passed": false,
+  "discoverySource": "task-plan",
+  "checks": [
+    {
+      "command": "cd frontend",
+      "exitCode": 0,
+      "durationMs": 8,
+      "verdict": "pass"
+    },
+    {
+      "command": "npx tsc --noEmit",
+      "exitCode": 1,
+      "durationMs": 842,
+      "verdict": "fail"
+    },
+    {
+      "command": "npm run build",
+      "exitCode": 254,
+      "durationMs": 100,
+      "verdict": "fail"
+    }
+  ],
+  "retryAttempt": 1,
+  "maxRetries": 2
+}

.gsd/milestones/M010/slices/S03/tasks/T02-SUMMARY.md

@@ -0,0 +1,75 @@
+---
+id: T02
+parent: S03
+milestone: M010
+provides: []
+requires: []
+affects: []
+key_files: ["frontend/src/App.css"]
+key_decisions: ["Applied animation via CSS selector list targeting existing page wrapper classes rather than adding .page-enter className to each TSX file"]
+patterns_established: []
+drill_down_paths: []
+observability_surfaces: []
+duration: ""
+verification_result: "TypeScript compilation (tsc --noEmit) and Vite production build both passed with zero errors."
+completed_at: 2026-03-31T06:27:10.192Z
+blocker_discovered: false
+---
+
+# T02: Added @keyframes pageEnter (opacity 0→1, translateY 8→0, 250ms ease-out) applied to all 7 public page wrapper classes via CSS selector list
+
+> Added @keyframes pageEnter (opacity 0→1, translateY 8→0, 250ms ease-out) applied to all 7 public page wrapper classes via CSS selector list
+
+## What Happened
+---
+id: T02
+parent: S03
+milestone: M010
+key_files:
+  - frontend/src/App.css
+key_decisions:
+  - Applied animation via CSS selector list targeting existing page wrapper classes rather than adding .page-enter className to each TSX file
+duration: ""
+verification_result: passed
+completed_at: 2026-03-31T06:27:10.192Z
+blocker_discovered: false
+---
+
+# T02: Added @keyframes pageEnter (opacity 0→1, translateY 8→0, 250ms ease-out) applied to all 7 public page wrapper classes via CSS selector list
+
+**Added @keyframes pageEnter (opacity 0→1, translateY 8→0, 250ms ease-out) applied to all 7 public page wrapper classes via CSS selector list**
+
+## What Happened
+
+Identified outermost wrapper classNames for all 7 public pages (.home, .topics-browse, .subtopic-page, .search-results-page, .creators-browse, .creator-detail, .technique-page). Added @keyframes pageEnter animation and applied it to all classes via a grouped CSS selector at the end of App.css. No TSX files modified — the animation triggers on mount automatically.
+
+## Verification
+
+TypeScript compilation (tsc --noEmit) and Vite production build both passed with zero errors.
+
+## Verification Evidence
+
+| # | Command | Exit Code | Verdict | Duration |
+|---|---------|-----------|---------|----------|
+| 1 | `cd frontend && npx tsc --noEmit` | 0 | ✅ pass | 2000ms |
+| 2 | `npm run build` | 0 | ✅ pass | 900ms |
+
+
+## Deviations
+
+None. Used the CSS-only approach (plan option #4) to avoid modifying 7 TSX files.
+
+## Known Issues
+
+None.
+
+## Files Created/Modified
+
+- `frontend/src/App.css`
+
+
+## Deviations
+None. Used the CSS-only approach (plan option #4) to avoid modifying 7 TSX files.
+
+## Known Issues
+None.

frontend/src/App.css

@@ -3728,3 +3728,26 @@ a.app-footer__about:hover,
     font-size: 1.5rem;
   }
 }
+
+/* ── Page-enter transition ────────────────────────────────────────────────── */
+
+@keyframes pageEnter {
+  from {
+    opacity: 0;
+    transform: translateY(8px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.home,
+.topics-browse,
+.subtopic-page,
+.search-results-page,
+.creators-browse,
+.creator-detail,
+.technique-page {
+  animation: pageEnter 250ms ease-out;
+}