✓ 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
Comprehensive, near-complete implementation with correct Archimedes physics, live readouts, animated two-phase crown fall/submersion, particle splashes, and a polished Heureka overlay — minor weakness is the slider lacks tactile visual feedback of crown position during the falling phase (0–30%), and water-rise pixel scaling is arbitrary rather than geometrically derived from tank dimensions.
Comprehensive, near-complete implementation with correct Archimedes physics, live readouts, animated two-phase crown fall/submersion, particle splashes, and a polished Heureka overlay — minor weakness is the slider lacks tactile visual feedback of crown position during the falling phase (0–30%), and water-rise pixel scaling is arbitrary rather than geometrically derived from tank dimensions.