✓ 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 (ρ_gold=19.3, ρ_fake=8.3 g/cm³, same 1000g mass), iterative water-rise calculation, live info panels, comparison bars, splash/ripple particles, refraction tinting, and a polished Heureka overlay — minor flaw is the vertical slider uses a non-standard CSS/attribute approach that may not render vertically in all browsers (Firefox ignores orient attribute without -moz- prefix).
Exceptionally complete implementation with correct physics (ρ_gold=19.3, ρ_fake=8.3 g/cm³, same 1000g mass), iterative water-rise calculation, live info panels, comparison bars, splash/ripple particles, refraction tinting, and a polished Heureka overlay — minor flaw is the vertical slider uses a non-standard CSS/attribute approach that may not render vertically in all browsers (Firefox ignores orient attribute without -moz- prefix).