springlet

A self-playing motion editor for UI components on a 12-second loop. The Switch component sits on a dot-grid canvas at 200% with its knob selected, a dashed motion path and an onion-skin ghost of each end position. A pointer presses play: the knob slides on a soft spring, stretching as it sets off, the track fills violet and glows, and the playhead runs over the timeline's keyframes. Then it drags Stiffness up and Damping down, and the spring's curve in the inspector and on the Position X track reshape live while the overshoot climbs from 3% to 42%. Played twice more, the knob bounces off and back on; the sliders go back and the knob slides home, closing the loop. Around it: a frosted sidebar with the layer tree and an easing library of spring thumbnails, a top bar with tools and Export, an inspector with an Ease / Spring / Bezier switch, and a timeline with four properties, their clips and a timecode. No images: HTML, CSS, SVG and canvas, Inter, Lucide icons, a 1600 × 1000 stage that scales to fit any window, and a frame-exact recorder (?rec and window.__render).