✓ 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 are implemented with correct physics (gold 19.3 g/cm³, gilded ~5.5 g/cm³, same 1000 g mass) and a polished Heureka overlay, but water-rise scaling uses an arbitrary fudge factor rather than a geometrically derived tank cross-section, and the buoyancy unit label "mN" is dimensionally inconsistent with the raw formula output.
All required features are implemented with correct physics (gold 19.3 g/cm³, gilded ~5.5 g/cm³, same 1000 g mass) and a polished Heureka overlay, but water-rise scaling uses an arbitrary fudge factor rather than a geometrically derived tank cross-section, and the buoyancy unit label "mN" is dimensionally inconsistent with the raw formula output.