✓ 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 (min=0 at top maps to air, but the HTML slider renders 0 at bottom by default, so crowns start at top visually yet at slider-bottom=water semantics are reversed); no smooth fall animation — crowns jump linearly with no timed drop sequence.
Slider direction is inverted (min=0 at top maps to air, but the HTML slider renders 0 at bottom by default, so crowns start at top visually yet at slider-bottom=water semantics are reversed); no smooth fall animation — crowns jump linearly with no timed drop sequence.