✓ 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 at top maps to crowns in air, but writing-mode bt-lr means the thumb starts at the bottom, making full submersion occur at slider top, not bottom); fall animation is absent — crowns teleport to position rather than animate falling.
Slider direction is inverted (min=0 at top maps to crowns in air, but writing-mode bt-lr means the thumb starts at the bottom, making full submersion occur at slider top, not bottom); fall animation is absent — crowns teleport to position rather than animate falling.