✓ 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 is inverted (min=0 at top maps to air, but the range input default orientation means dragging up goes toward 0/air which could be correct, however the CSS rotation trick and the mapping of depthPercent mean crowns start at top position at value=0 and descend at value=100, which is actually correct directionally — but the water appears immediately from the bottom-up in a physically implausible way since water starts at y=550 and rises, yet the container has no pre-existing water baseline, making it look like water materializes rather than crown entering existing water; additionally, the splash fires indiscriminately during the 30–95% range rather than only at water-entry moment, and the displaced-water calculation uses a trivially small fraction of container area making water level changes nearly invisible.
Slider is inverted (min=0 at top maps to air, but the range input default orientation means dragging up goes toward 0/air which could be correct, however the CSS rotation trick and the mapping of depthPercent mean crowns start at top position at value=0 and descend at value=100, which is actually correct directionally — but the water appears immediately from the bottom-up in a physically implausible way since water starts at y=550 and rises, yet the container has no pre-existing water baseline, making it look like water materializes rather than crown entering existing water; additionally, the splash fires indiscriminately during the 30–95% range rather than only at water-entry moment, and the displaced-water calculation uses a trivially small fraction of container area making water level changes nearly invisible.