Make one UI component in a single web page: a toggle switch that people want to keep clicking forever. The switch is a wide pill. Its track is a window into a tiny living pixel-art world: a lighthouse on a cliff above the sea, a small keeper who walks around, waves rolling in, gulls, drifting clouds. The knob is a glass marble that slides along the track and refracts the scene behind it like a real lens. Off is day, on is night. When it switches, the world changes over about a second with a dithered sunset or sunrise: the sky shifts, the lighthouse lamp turns on and sweeps the sea, the moon and stars come out. The page background changes with it. The click should feel physical: the knob squashes, overshoots and settles, with a soft click made in code. Make all the art in code (canvas or WebGL, no image files, no image or video models). Put everything in one self-contained index.html with no network requests. It has to work with mouse, touch and keyboard (space or enter), and it should look and feel like a finished product, not a demo. Test it in a headless browser, including toggling it several times, before you finish.