✓ 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
All required features implemented correctly with accurate physics (gold 19.3 g/cm³, alloy 13.0 g/cm³, same 1000 g mass); main weakness is mass/volume/density values are static text rather than dynamically updating, and crown-submerged rendering relies on translateY overflow rather than a true in-tank clipping/rendering pass, making the submerged visual slightly crude.
All required features implemented correctly with accurate physics (gold 19.3 g/cm³, alloy 13.0 g/cm³, same 1000 g mass); main weakness is mass/volume/density values are static text rather than dynamically updating, and crown-submerged rendering relies on translateY overflow rather than a true in-tank clipping/rendering pass, making the submerged visual slightly crude.