✓ 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 → crowns in air is visually correct here, but the vertical slider's `writing-mode: bt-lr` combined with `min=0 top` means dragging down increases value, making top=submerged and bottom=air in practice); fall animation is absent — crowns teleport linearly with no gravity/drop sequence.
Slider direction is inverted (value=0 → crowns in air is visually correct here, but the vertical slider's `writing-mode: bt-lr` combined with `min=0 top` means dragging down increases value, making top=submerged and bottom=air in practice); fall animation is absent — crowns teleport linearly with no gravity/drop sequence.