Title: Physics Orbits — Gravity Bench
Prompt: Build a tiny N-body gravity bench with a central star where visitors drag to aim launch vectors and fire planets into orbit. Collisions should merge, escapees should count, and trails should paint the transfer ellipses. Keep the mood like a mission-control console in gold and ice-blue.
Design: A monospace console layout with a gridded black canvas beside a parameter sidebar in deep navy; gold central star with ice and green planet trails, plus a four-stat strip with four deliberately different corner radii.
Visual techniques:
- Symplectic-Euler N-body integration with softening and substeps
- Fading per-body trail buffers drawn as stroked polylines
- Radial-gradient glow sprites for stars and planets
- Drag-aim vector overlay with dashed prediction line
- Blinking live indicator and FPS/energy HUD via CSS keyframes
Interaction model: Drag and release on canvas fires a planet with velocity from the drag vector, plain click seeds a planet and shift-click drops a heavy star, sliders retune gravity, trail length, time warp and softening, toggles control grid, trails, merging and pause, and fleet/clear buttons inject or reset bodies.