✓ 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 Archimedes physics (gold 19.3 g/cm³, gilded 5.2 g/cm³, same 1000 g mass), animated SVG crowns, rising water levels, splash effects, live info panels, and a polished Heureka overlay — minor flaw: the water-rise pixel scaling (maxRiseGold=15px, maxRiseFake=55px) is hand-tuned rather than derived from actual container geometry, and the buoyancy unit label "mN" is technically correct only if treating cm³ numerically as if they were liters, making the displayed force values off by ~1000×.
Exceptionally complete implementation with correct Archimedes physics (gold 19.3 g/cm³, gilded 5.2 g/cm³, same 1000 g mass), animated SVG crowns, rising water levels, splash effects, live info panels, and a polished Heureka overlay — minor flaw: the water-rise pixel scaling (maxRiseGold=15px, maxRiseFake=55px) is hand-tuned rather than derived from actual container geometry, and the buoyancy unit label "mN" is technically correct only if treating cm³ numerically as if they were liters, making the displayed force values off by ~1000×.