Horizontal Scroll Scenes

Build scene-by-scene chapters that advance left to right on one fixed stage while the user scrolls vertically, with native scroll as the only input. One pure function turns scrollY into scene, dwell and move, so forward, reverse, scrollbar drags, fast skips and reload at depth all land on the right frame. Covers dwell versus transition budgets, a burn-wipe or pan between scenes, chapter index and progress UI, glide-to-scene links that skip intermediate scenes, keyboard and reduced-motion behaviour. Use for horizontal scrollytelling, multi-scene product tours, "scroll down to travel sideways", chapter carousels driven by the wheel, or any piece where a wheel-jacked slider …