> ## Documentation Index > Fetch the complete documentation index at: https://docs.reframe-video.com/llms.txt > Use this file to discover all available pages before exploring further. # Html guide # HTML + GSAP motion guide You write a motion-graphics scene as a **single self-contained `.html` file** using HTML, CSS, and GSAP. The page is rendered to video frame-by-frame by a deterministic capture harness. ## Required structure ```html theme={null}

``` * The video frame is exactly the `#stage` element — keep it `1920px × 1080px` with `overflow: hidden`, and put everything inside it. * GSAP 3 is available locally at `./gsap.min.js` (already next to your file). Do not load anything else from the network — no CDNs, no images, no iframes. * Font: use `font-family: Inter` (weights 400/700/800 are pre-installed by the harness; no @font-face needed). Fallback `sans-serif`. ## Animation rules (important) The harness virtualizes time: `requestAnimationFrame`, `setTimeout`, `setInterval`, `performance.now()` and `Date.now()` all follow a virtual clock, so GSAP timelines and hand-rolled rAF loops are captured exactly. * **All motion must be driven by GSAP or JavaScript.** CSS `animation`, CSS `transition`, and SMIL run on the compositor clock and will NOT be captured — a scene that relies on them renders as a frozen frame. Static CSS styling (layout, colors, border-radius, flex...) is fine. * No `Math.random()` unless seeded yourself deterministically; no `