✓ 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 is top/air but slider renders 0 at bottom in bt-lr mode, meaning bottom=air, top=water); no smooth fall animation — crowns teleport via transform with no easing or motion trajectory.
Slider direction is inverted (value=0 is top/air but slider renders 0 at bottom in bt-lr mode, meaning bottom=air, top=water); no smooth fall animation — crowns teleport via transform with no easing or motion trajectory.