✓ 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 bottom means air, value=100 at top means water, but `writing-mode: bt-lr` and `slider-vertical` render it bottom-up making slider-top = crown in water = wrong per spec); live mass/volume/density per-crown are absent; buoyancy force formula omits g (9.81), so "N" values are actually in gram-force; crown rotation during fall is physically implausible; gilded crown correctly displaces more water, but submerged ratio only activates after 40% slider progress, wasting the lower range.
Slider direction is inverted (value=0 at bottom means air, value=100 at top means water, but `writing-mode: bt-lr` and `slider-vertical` render it bottom-up making slider-top = crown in water = wrong per spec); live mass/volume/density per-crown are absent; buoyancy force formula omits g (9.81), so "N" values are actually in gram-force; crown rotation during fall is physically implausible; gilded crown correctly displaces more water, but submerged ratio only activates after 40% slider progress, wasting the lower range.