— Two crowns — Same mass, different density — Vertical slider ✓ Slider works — Slider controls crowns — Slider direction correct — Full slider range — Fall animation ✓ Water displacement ✓ Rising water level — Splash effects — Physics correct — Live mass value — Live volume value — Live density value ✓ Live displaced water — Gilded displaces more — Heureka animation ✓ No external deps ✓ Light bg / dark text ✓ Self-contained HTML
Completely off-brief: implements a generic single-object buoyancy toy with horizontal sliders instead of two crowns (pure gold vs. gilded) with a vertical immersion slider, missing every crown-specific requirement — no crowns, no Heureka moment, no fall/splash animation, no density comparison, no vertical slider.
Completely off-brief: implements a generic single-object buoyancy toy with horizontal sliders instead of two crowns (pure gold vs. gilded) with a vertical immersion slider, missing every crown-specific requirement — no crowns, no Heureka moment, no fall/splash animation, no density comparison, no vertical slider.