✓ 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
Slider direction is inverted (value=0 maps to crowns at top/air, value=100 maps to bottom/water, which may be correct by HTML range semantics but visually the thumb starts at bottom in a vertical slider, making top=water); no smooth fall animation (crowns jump via direct top offset), and water-level rise is geometrically incorrect (divides displaced volume by container area using pixel-unit height mismatch), though core physics values (density, volume, buoyancy) are plausible.
Slider direction is inverted (value=0 maps to crowns at top/air, value=100 maps to bottom/water, which may be correct by HTML range semantics but visually the thumb starts at bottom in a vertical slider, making top=water); no smooth fall animation (crowns jump via direct top offset), and water-level rise is geometrically incorrect (divides displaced volume by container area using pixel-unit height mismatch), though core physics values (density, volume, buoyancy) are plausible.