✓ 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 at top = crowns in air is technically correct per HTML default but the slider reads min=0 at "OBEN"/top and max=100 at "UNTEN"/bottom with writing-mode bt-lr, which may render upside-down in browsers — critical UX ambiguity); no smooth fall animation (crowns teleport linearly with slider drag rather than animating independently); splash logic fires continuously on drag rather than only at the moment of water entry.
Slider direction is inverted (value=0 at top = crowns in air is technically correct per HTML default but the slider reads min=0 at "OBEN"/top and max=100 at "UNTEN"/bottom with writing-mode bt-lr, which may render upside-down in browsers — critical UX ambiguity); no smooth fall animation (crowns teleport linearly with slider drag rather than animating independently); splash logic fires continuously on drag rather than only at the moment of water entry.