---
id: S06
parent: M016
milestone: M016
provides:
  - Animated stat count-up on homepage
  - Unified .section-heading utility class
  - Header brand accent line
requires:
  - slice: S01
    provides: Consistent 42rem max-width and spacing baseline
  - slice: S03
    provides: Brand identity (logo SVG, cyan accent color)
affects:
  []
key_files:
  - frontend/src/hooks/useCountUp.ts
  - frontend/src/App.css
  - frontend/src/pages/Home.tsx
key_decisions:
  - Made useCountUp generic over element type for React 18 ref compatibility
  - Kept section-specific CSS classes as empty shells for future BEM overrides rather than deleting them
patterns_established:
  - useCountUp hook pattern: IntersectionObserver + rAF + ease-out for scroll-triggered number animation, reusable across any numeric display
observability_surfaces:
  - none
drill_down_paths:
  - .gsd/milestones/M016/slices/S06/tasks/T01-SUMMARY.md
  - .gsd/milestones/M016/slices/S06/tasks/T02-SUMMARY.md
duration: ""
verification_result: passed
completed_at: 2026-04-03T06:23:12.920Z
blocker_discovered: false
---

# S06: Landing Page Personality Pass

**Homepage gets animated stat count-up, unified section headings, tighter above-fold layout, and header brand accent line.**

## What Happened

Two tasks polished the homepage personality. T01 created a reusable `useCountUp` hook (`frontend/src/hooks/useCountUp.ts`) that animates numbers from 0 to target using requestAnimationFrame with cubic ease-out timing, triggered by IntersectionObserver when the stats section scrolls into view. The hook is generic over element type for React 18 ref compatibility, fires once per mount, and handles async data loading (stats arriving after initial render). Wired into Home.tsx for both technique_count and creator_count.

T02 made three CSS/JSX changes: (1) Created `.section-heading` utility class with `--accent` modifier, applied to all four homepage section headings (Popular Topics, Trending Searches, Featured Technique, Recently Added), stripping duplicated font-size/weight/transform/spacing from individual selectors. (2) Tightened above-fold spacing — reduced hero padding, value-prop margin, and how-it-works gap so more content is visible without scrolling on a 900px viewport. (3) Added `border-bottom: 2px solid var(--color-accent)` to `.app-header` for brand accent continuity with the cyan logo.

## Verification

All slice-level verification checks pass:
- `npx tsc --noEmit` — zero errors
- `npm run build` — 59 modules, 920ms, zero warnings
- `useCountUp.ts` exists in hooks directory
- `Home.tsx` imports and uses `useCountUp`
- `section-heading` class defined in App.css and used in Home.tsx
- `border-bottom.*accent` present in App.css

## Requirements Advanced

- R037 — Stats scorecard now has animated count-up. Section headings use unified treatment. Above-fold content tightened. Header has brand accent. All S06 criteria from R037 supporting slices met.

## Requirements Validated

None.

## New Requirements Surfaced

None.

## Requirements Invalidated or Re-scoped

None.

## Deviations

T01: Made useCountUp generic over HTMLElement type (`useCountUp&lt;T extends HTMLElement&gt;`) for React 18 strict ref typing — minor deviation, required by type system.

## Known Limitations

None.

## Follow-ups

None.

## Files Created/Modified

- `frontend/src/hooks/useCountUp.ts` — New reusable hook: IntersectionObserver-triggered rAF count-up animation with ease-out timing
- `frontend/src/pages/Home.tsx` — Wired useCountUp for technique_count and creator_count; added section-heading classes to all four heading elements
- `frontend/src/App.css` — Added .section-heading utility class + --accent modifier; tightened hero/how-it-works spacing; added header border-bottom accent; stripped duplicated heading declarations
