✓ 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 (dragging down = entering water, which is correct mechanically, but top=air/bottom=water mapping means the label says LUFT at top which is fine — actually direction IS correct); no smooth fall animation (crown teleports via ASCII re-render); ASCII art canvas is functional but visually crude, and sparkle/water randomness causes flickering on every 100ms interval tick even when not interacting.
Slider direction is inverted (dragging down = entering water, which is correct mechanically, but top=air/bottom=water mapping means the label says LUFT at top which is fine — actually direction IS correct); no smooth fall animation (crown teleports via ASCII re-render); ASCII art canvas is functional but visually crude, and sparkle/water randomness causes flickering on every 100ms interval tick even when not interacting.