✓ 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, well-polished implementation hitting every required feature with correct physics (ρ_gold=19.3, ρ_gilded=6.0, same 1000g mass, 3.22× volume ratio) and a full Heureka overlay, but water-rise scale is an arbitrary visual constant (0.35 px/cm³) rather than geometrically derived, slightly undermining physical rigor.
Comprehensive, well-polished implementation hitting every required feature with correct physics (ρ_gold=19.3, ρ_gilded=6.0, same 1000g mass, 3.22× volume ratio) and a full Heureka overlay, but water-rise scale is an arbitrary visual constant (0.35 px/cm³) rather than geometrically derived, slightly undermining physical rigor.