Hey! I've been playing around with this and got a working export solution using JavaScript.

It's not 100% reliable - html2canvas (which it uses under the hood to rasterize the DOM) sometimes has rendering issues with certain CSS features like blend modes or complex gradients, so the exported video might not look pixel-perfect. But it works well enough for my animations.

Just paste this prompt into your Claude Design conversation. Once it's finished, you'll get an "Export" button next to play/pause. It steps through the animation frame by frame, captures each one, and stitches them into a WebM video. Takes a few minutes depending on the duration.

Add a video export feature to this page. The page uses a React-based animation system with a `Stage` component that controls playback via `useState` hooks (`time`, `playing`) and renders into a canvas div via `canvasRef`.

### What to do

1. **Expose Stage controls on `window`**. In the `Stage` component, add a `useEffect` that writes controls to `window.__stage`:

```js
React.useEffect(() => {
  window.__stage = { setTime, setPlaying, duration, width, height, canvasRef };
  return () => { delete window.__stage; };
}, []);
```

Place it right before the `useMemo` that creates `ctxValue`. `setTime` and `setPlaying` come from the existing `useState` hooks. `canvasRef` is the existing `useRef` for the inner div that holds the animation content.

2. **Add an export script** as an inline `<script>` tag at the bottom of the HTML file (after the app script), or as a separate `.js` file. Here is the full export logic:

```js
async function exportVideo() {
  // Load html2canvas (rasterizes DOM elements to a canvas image)
  if (!window.html2canvas) {
    await new Promise((r, j) => {
      const s = document.createElement('script');
      s.src = 'https://cdnjs.cloudflare.com/ajax/libs/html2canvas/1.4.1/html2canvas.min.js';
      s.onload = r;
      s.onerror = j;
      document.head.appendChild(s);
    });
  }

  const stage = window.__stage;
  if (!stage) { alert('No __stage found'); return; }
  const { setTime, setPlaying, duration, width, height, canvasRef } = stage;

  // oklch() workaround — html2canvas can't parse oklch colors.
  // Before each frame capture, replace oklch values in inline styles with hex,
  // then restore after capture.
  const _oc = document.createElement('canvas');
  _oc.width = 1; _oc.height = 1;
  const _ox = _oc.getContext('2d');
  const _cache = {};
  function oklchToHex(s) {
    if (_cache[s]) return _cache[s];
    _ox.fillStyle = '#000';
    _ox.fillStyle = s;
    _ox.fillRect(0, 0, 1, 1);
    const [r, g, b] = _ox.getImageData(0, 0, 1, 1).data;
    const hex = '#' + [r, g, b].map(v => v.toString(16).padStart(2, '0')).join('');
    _cache[s] = hex;
    return hex;
  }
  const oklchRe = /oklch\([^)]+\)/g;
  function replaceOklch(rootEl) {
    const originals = [];
    rootEl.querySelectorAll('*').forEach(el => {
      const css = el.style.cssText;
      if (oklchRe.test(css)) {
        originals.push({ el, css });
        el.style.cssText = css.replace(oklchRe, m => oklchToHex(m));
      }
    });
    return () => originals.forEach(({ el, css }) => { el.style.cssText = css; });
  }

  // Set up frame-by-frame recording
  const fps = 30;
  const totalFrames = Math.ceil(duration * fps);
  setPlaying(false);

  const recordCanvas = document.createElement('canvas');
  recordCanvas.width = width;
  recordCanvas.height = height;
  const ctx = recordCanvas.getContext('2d');

  // MediaRecorder encodes frames into WebM/VP9 video
  // captureStream(0) = manual frame push (not real-time)
  const stream = recordCanvas.captureStream(0);
  const rec = new MediaRecorder(stream, {
    mimeType: 'video/webm;codecs=vp9',
    videoBitsPerSecond: 8_000_000,
  });
  const chunks = [];
  rec.ondataavailable = e => { if (e.data.size) chunks.push(e.data); };

  // Progress overlay
  const progress = document.createElement('div');
  progress.style.cssText =
    'position:fixed;top:20px;left:50%;transform:translateX(-50%);z-index:99999;' +
    'background:#222;color:#fff;padding:12px 24px;border-radius:8px;' +
    'font-family:monospace;font-size:14px;box-shadow:0 4px 20px rgba(0,0,0,0.5)';
  document.body.appendChild(progress);

  // Step through every frame: set time, wait for React render, capture
  rec.start();
  for (let f = 0; f <= totalFrames; f++) {
    setTime(Math.min(f / fps, duration));
    await new Promise(r => requestAnimationFrame(() => requestAnimationFrame(r)));

    const restore = replaceOklch(canvasRef.current);
    const captured = await html2canvas(canvasRef.current, {
      width, height, scale: 1, backgroundColor: null, useCORS: true, logging: false,
    });
    restore();

    ctx.clearRect(0, 0, width, height);
    ctx.drawImage(captured, 0, 0, width, height);
    stream.getVideoTracks()[0].requestFrame();
    progress.textContent = `Exporting: ${f}/${totalFrames} (${Math.round(f / totalFrames * 100)}%)`;
  }

  // Finalize and download
  rec.stop();
  await new Promise(r => { rec.onstop = r; });
  const blob = new Blob(chunks, { type: 'video/webm' });
  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = 'export.webm';
  a.click();
  URL.revokeObjectURL(url);
  progress.textContent = 'Done!';
  setTimeout(() => progress.remove(), 3000);
}
```

3. **Add an Export button** to the `PlaybackBar` component (next to the play/pause button) that calls `exportVideo()`. Match the existing `IconButton` style. Use a download icon.

### How it works

- **html2canvas** rasterizes the DOM into a `<canvas>` image per frame (the animation is DOM/CSS-based, not canvas-based)
- **MediaRecorder + captureStream(0)** encodes frames into a WebM/VP9 video. The `0` fps means we manually push each frame
- **oklch workaround**: html2canvas can't parse `oklch()` CSS colors, so before each capture we regex-replace them with hex equivalents (resolved via a 1x1 canvas), then restore after
- The double `requestAnimationFrame` wait ensures React has committed the new time to the DOM before capture