Section Héros 3D Animé avec Vidéo Pilotée par le Défilement

Build a single-page fullscreen hero section for a brand called "SynapseX" using React, Vite, Tailwind CSS v4, and Framer Motion (`motion/react`). Use the `lenis` library for smooth scrolling on desktop. The page is a dark, cinematic fullscreen video-backed landing with scroll-driven animations and text scramble effects. --- **Tech stack:** - React 19, Vite, TypeScript - Tailwind CSS v4 (via `@tailwindcss/vite` plugin) - `motion` (Framer Motion v12+, imported from `motion/react`) - `lenis` for smooth scroll on desktop only - Font: "Space Mono" monospace from Google Fonts (used for ALL font families: sans, serif, mono) - Bootstrap Icons CDN for the Apple icon (`bi bi-apple`) --- **Font / CSS setup (`index.css`):** - Import Google Fonts: `Space Mono` (400, 700, italic variants) - Import Bootstrap Icons CSS from jsdelivr CDN - Import `tailwindcss` - Override all Tailwind font theme vars (`--font-sans`, `--font-serif`, `--font-inter`, `--font-mono`) to `"Space Mono", monospace` - `html, body`: font-family var(--font-sans), bg black, color white, no margin/padding, overflow-x hidden, overflow-y auto - Lenis compatibility classes (`.lenis.lenis-smooth`, `.lenis.lenis-stopped`, `.lenis.lenis-scrolling iframe`) --- **Background video (CRITICAL - read carefully):** - URL: `https://t.co/cvkGVS5C0E` - Rendered in a `LiquidVideoCanvas` component: a fixed fullscreen `<video>` element (loop, muted, playsInline, preload="auto", object-cover) **IMPORTANT - NO DARK OVERLAY:** The video container must have NO dark overlay, NO semi-transparent black layer, NO `bg-black/50`, NO `::after` pseudo-element with opacity, and NO gradient overlay on top of the video. The video should be fully visible at its natural brightness. The only container background should be `bg-black` on the wrapper div itself (visible only before the video loads). Do NOT add any darkening filter, overlay div, or tint on top of the video. **IMPORTANT - Z-INDEX LAYERING (must follow exactly):** - Video container: `fixed inset-0 z-[1]` - this is the LOWEST layer - Progressive blur: `fixed bottom-0 z-30` - Main content (text, headings): `z-10` (above video, below header) - Header: `z-50` (topmost) - The root wrapper is `relative` with `overflow-x-hidden`. The main content area must NOT have a background color that would obscure the video. The video must always be VISIBLE through the content layers. Do NOT set `bg-black` on any element that sits above the video container. **Video scroll-scrubbing (CRITICAL - frame seeking logic):** - The video is NOT autoplayed. Its `currentTime` is driven by scroll progress via requestAnimationFrame with LERP smoothing (factor 0.12). - **Frame-accurate seeking with `if (!video.seeking)` guard:** Only request a new video frame seek when the browser has completely finished rendering the previous frame. This prevents frame-skipping, jank, and black flashes. The pattern: ``` if (!isSeeking && !video.seeking) { isSeeking = true; video.currentTime = clampedTime; } else { nextSeekTime = clampedTime; // queue for after current seek completes } ``` We tell the browser: "Update the video frame ONLY when you have completely finished painting the previous one." This is essential for smooth, buttery playback on all devices. Without this guard, multiple overlapping seeks cause the video to show black frames or stutter. - Listen for `seeking` and `seeked` events on the video element. On `seeked`, check if there's a queued `nextSeekTime` and execute it. **Entrance animation:** - Starts at scale 1.12, opacity 0. On video `readyState >= 3`, animates over 1.4s with cubic ease-out to scale 1.0, opacity 1. Has a 3.5s safety timeout fallback. **Scroll-driven visual effects (applied directly to DOM via ref, NOT via React state):** - Progressive blur: 0-55px based on scroll (subtle base 0-5px in first half, then aggressive 5-55px in second half).