✓ 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
Exceptionally complete implementation with correct physics (same mass, gold ρ=19300, fake ρ=8500), live buoyancy/displaced-volume readouts, animated water rise, splash particles, force arrows, and a polished Heureka overlay — minor flaw: the underwater crown rendering uses a simplistic blue rectangle overlay rather than re-clipping the actual crown shape.
Exceptionally complete implementation with correct physics (same mass, gold ρ=19300, fake ρ=8500), live buoyancy/displaced-volume readouts, animated water rise, splash particles, force arrows, and a polished Heureka overlay — minor flaw: the underwater crown rendering uses a simplistic blue rectangle overlay rather than re-clipping the actual crown shape.