feat: replace CSS hero motif with a real WebGL 3D braided-crown scene

Adds Hero3DScene, a procedurally-built rotating braid mesh rendered via
@react-three/fiber, replacing the flat CSS-circle Hero3D component. Falls
back to a static gradient circle under prefers-reduced-motion, matching the
old component's fallback behavior.

Also adds a ResizeObserver mock to the test setup, required by
@react-three/fiber's Canvas (via react-use-measure) in jsdom, which doesn't
implement it natively.

src/components/Hero3D.test.tsx

@@ -1,37 +0,0 @@
-import { render, screen } from '@testing-library/react'
-import { describe, it, expect, vi, afterEach, beforeEach } from 'vitest'
-
-describe('Hero3D', () => {
-  beforeEach(() => {
-    vi.resetModules()
-  })
-
-  afterEach(() => vi.restoreAllMocks())
-
-  it('renders the motif container', async () => {
-    vi.doMock('framer-motion', async () => {
-      const actual = await vi.importActual('framer-motion')
-      return {
-        ...actual,
-        useReducedMotion: () => false,
-      }
-    })
-    const { default: Hero3D } = await import('./Hero3D')
-    render(<Hero3D />)
-    expect(screen.getByTestId('hero-3d')).toBeInTheDocument()
-  })
-
-  it('renders statically when reduced motion is preferred', async () => {
-    vi.doMock('framer-motion', async () => {
-      const actual = await vi.importActual('framer-motion')
-      return {
-        ...actual,
-        useReducedMotion: () => true,
-      }
-    })
-    const { default: Hero3D } = await import('./Hero3D')
-    render(<Hero3D />)
-    expect(screen.getByTestId('hero-3d')).toBeInTheDocument()
-    expect(screen.getByTestId('hero-3d-motif').className).toMatch(/static/)
-  })
-})

src/components/Hero3D.tsx

@@ -1,25 +0,0 @@
-import { motion, useReducedMotion, useScroll, useTransform } from 'framer-motion'
-import styles from './Hero3D.module.css'
-
-function Hero3D() {
-  const prefersReducedMotion = useReducedMotion()
-  const { scrollY } = useScroll()
-  const rotateY = useTransform(scrollY, [0, 600], [0, 180])
-  const rotateX = useTransform(scrollY, [0, 600], [0, 20])
-
-  if (prefersReducedMotion) {
-    return (
-      <div className={styles.wrapper} data-testid="hero-3d">
-        <div className={styles.static} data-testid="hero-3d-motif" />
-      </div>
-    )
-  }
-
-  return (
-    <div className={styles.wrapper} data-testid="hero-3d">
-      <motion.div className={styles.motif} style={{ rotateY, rotateX }} />
-    </div>
-  )
-}
-
-export default Hero3D

src/components/Hero3DScene.module.css

@@ -1,18 +1,16 @@
 .wrapper {
-  perspective: 900px;
-  width: 220px;
-  height: 220px;
+  width: 280px;
+  height: 280px;
   margin: 0 auto;
 }
 
-.motif {
+.wrapper canvas {
+  outline: none;
+}
+
+.fallbackMotif {
   width: 100%;
   height: 100%;
   border-radius: 50%;
   background: radial-gradient(circle at 30% 30%, #e6c98f, var(--color-gold));
-  transform-style: preserve-3d;
-}
-
-.static {
-  composes: motif;
 }

src/components/Hero3DScene.test.tsx

@@ -0,0 +1,44 @@
+import { render, screen } from '@testing-library/react'
+import { describe, it, expect, vi, afterEach } from 'vitest'
+
+vi.mock('@react-three/fiber', () => ({
+  Canvas: ({ children }: { children?: React.ReactNode }) => <div data-testid="r3f-canvas">{children}</div>,
+  useFrame: () => {},
+}))
+
+describe('Hero3DScene', () => {
+  afterEach(() => {
+    vi.restoreAllMocks()
+  })
+
+  it('renders the static fallback and no canvas when reduced motion is preferred', async () => {
+    vi.resetModules()
+    vi.doMock('framer-motion', async () => {
+      const actual = await vi.importActual('framer-motion')
+      return {
+        ...actual,
+        useReducedMotion: () => true,
+      }
+    })
+    const { default: Hero3DScene } = await import('./Hero3DScene')
+    render(<Hero3DScene />)
+    const wrapper = screen.getByTestId('hero-3d-scene')
+    expect(wrapper.className).toMatch(/static/)
+    expect(screen.queryByTestId('r3f-canvas')).not.toBeInTheDocument()
+  })
+
+  it('renders the WebGL canvas when motion is allowed', async () => {
+    vi.resetModules()
+    vi.doMock('framer-motion', async () => {
+      const actual = await vi.importActual('framer-motion')
+      return {
+        ...actual,
+        useReducedMotion: () => false,
+      }
+    })
+    const { default: Hero3DScene } = await import('./Hero3DScene')
+    render(<Hero3DScene />)
+    expect(screen.getByTestId('hero-3d-scene')).toBeInTheDocument()
+    expect(screen.getByTestId('r3f-canvas')).toBeInTheDocument()
+  })
+})

src/components/Hero3DScene.tsx

@@ -0,0 +1,92 @@
+import { useMemo, useRef } from 'react'
+import { Canvas, useFrame } from '@react-three/fiber'
+import * as THREE from 'three'
+import { useReducedMotion, useScroll, useTransform, type MotionValue } from 'framer-motion'
+import styles from './Hero3DScene.module.css'
+
+const GOLD = '#B08D57'
+const STRAND_COUNT = 6
+
+interface BraidStrandProps {
+  radius: number
+  angleOffset: number
+}
+
+function BraidStrand({ radius, angleOffset }: BraidStrandProps) {
+  const geometry = useMemo(() => {
+    const points: THREE.Vector3[] = []
+    const segments = 20
+    for (let i = 0; i <= segments; i++) {
+      const t = i / segments
+      const angle = angleOffset + t * Math.PI * 0.6
+      const r = radius * (1 - t * 0.3)
+      points.push(new THREE.Vector3(Math.cos(angle) * r, t * 1.6 - 0.8, Math.sin(angle) * r))
+    }
+    const curve = new THREE.CatmullRomCurve3(points)
+    return new THREE.TubeGeometry(curve, 40, 0.05, 8, false)
+  }, [radius, angleOffset])
+
+  return (
+    <mesh geometry={geometry}>
+      <meshStandardMaterial color={GOLD} metalness={0.6} roughness={0.35} />
+    </mesh>
+  )
+}
+
+interface BraidedCrownProps {
+  scrollTilt: MotionValue<number>
+}
+
+function BraidedCrown({ scrollTilt }: BraidedCrownProps) {
+  const groupRef = useRef<THREE.Group>(null)
+
+  useFrame((_state, delta) => {
+    if (!groupRef.current) return
+    groupRef.current.rotation.y += delta * 0.25
+    groupRef.current.rotation.x = scrollTilt.get()
+  })
+
+  const strands = useMemo(
+    () =>
+      Array.from({ length: STRAND_COUNT }, (_, i) => ({
+        radius: 1.1,
+        angleOffset: (i / STRAND_COUNT) * Math.PI * 2,
+      })),
+    [],
+  )
+
+  return (
+    <group ref={groupRef}>
+      {strands.map((s, i) => (
+        <BraidStrand key={i} radius={s.radius} angleOffset={s.angleOffset} />
+      ))}
+    </group>
+  )
+}
+
+function Hero3DScene() {
+  const prefersReducedMotion = useReducedMotion()
+  const { scrollY } = useScroll()
+  const scrollTilt = useTransform(scrollY, [0, 600], [0, 0.35])
+
+  if (prefersReducedMotion) {
+    return (
+      <div className={`${styles.wrapper} static`} data-testid="hero-3d-scene">
+        <div className={styles.fallbackMotif} />
+      </div>
+    )
+  }
+
+  return (
+    <div className={styles.wrapper} data-testid="hero-3d-scene" aria-hidden="true">
+      <Canvas camera={{ position: [0, 0, 4], fov: 45 }}>
+        <ambientLight intensity={0.4} />
+        <directionalLight position={[2, 3, 4]} intensity={1.1} />
+        <directionalLight position={[-2, -1, -3]} intensity={0.3} />
+        <BraidedCrown scrollTilt={scrollTilt} />
+      </Canvas>
+    </div>
+  )
+}
+
+export default Hero3DScene

src/pages/Home.tsx

@@ -1,5 +1,5 @@
 import { Link, useNavigate } from 'react-router-dom'
-import Hero3D from '../components/Hero3D'
+import Hero3DScene from '../components/Hero3DScene'
 import ScrollReveal from '../components/ScrollReveal'
 import ServiceCard from '../components/ServiceCard'
 import { services } from '../data/services'
@@ -18,7 +18,7 @@ function Home() {
   return (
     <div>
       <section className={styles.hero}>
-        <Hero3D />
+        <Hero3DScene />
         <h1 className={styles.headline}>Your hair, your crown</h1>
         <p className={styles.tagline}>Protective Styles by Mira</p>
         <div className={styles.ctas}>

src/test/setup.ts

@@ -10,6 +10,15 @@ class MockIntersectionObserver {
 
 globalThis.IntersectionObserver = MockIntersectionObserver as unknown as typeof IntersectionObserver
 
+// Mock ResizeObserver (required by @react-three/fiber's Canvas, via react-use-measure)
+class MockResizeObserver {
+  observe = vi.fn()
+  unobserve = vi.fn()
+  disconnect = vi.fn()
+}
+
+globalThis.ResizeObserver = MockResizeObserver as unknown as typeof ResizeObserver
+
 // Setup matchMedia mock for framer-motion's useReducedMotion
 // Make it writable so tests can override it
 Object.defineProperty(window, 'matchMedia', {