✓ 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 (label says "drag up" but HTML range inputs with slider-vertical increase value upward, mapping top=submerged instead of top=air); no fall animation (crowns teleport rather than drop); splash fires continuously on every input event rather than once on water entry.
Slider direction is inverted (label says "drag up" but HTML range inputs with slider-vertical increase value upward, mapping top=submerged instead of top=air); no fall animation (crowns teleport rather than drop); splash fires continuously on every input event rather than once on water entry.