✓ 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 crown at top/air, but the crown Y transform subtracts from 120 making it move up as value increases — actually the slider's natural bottom=0 is air and top=100 is water, which is backward for a vertical range input whose visual "bottom" is 0); no smooth fall animation (crowns teleport via transform with no easing), and splash circles appear at incorrect fixed y-coordinates rather than at the actual water surface.
Slider direction is inverted (value=0 maps to crown at top/air, but the crown Y transform subtracts from 120 making it move up as value increases — actually the slider's natural bottom=0 is air and top=100 is water, which is backward for a vertical range input whose visual "bottom" is 0); no smooth fall animation (crowns teleport via transform with no easing), and splash circles appear at incorrect fixed y-coordinates rather than at the actual water surface.