✓ 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 maps to crowns in air at top, sliding down increases depth, but the native vertical slider renders top=max, so user dragging up increases depth — effectively top=water, bottom=air); no live volume/density readouts, no smooth fall animation (crowns teleport linearly with no physics).
Slider direction is inverted (min=0 maps to crowns in air at top, sliding down increases depth, but the native vertical slider renders top=max, so user dragging up increases depth — effectively top=water, bottom=air); no live volume/density readouts, no smooth fall animation (crowns teleport linearly with no physics).