✓ 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 at top means crowns start above water but increasing slider value moves crownY upward via negative offset, sending crowns out of view rather than into water); no smooth fall animation — crown jumps position directly with slider input.
Slider direction is inverted (value=0 at top means crowns start above water but increasing slider value moves crownY upward via negative offset, sending crowns out of view rather than into water); no smooth fall animation — crown jumps position directly with slider input.