✓ 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 "in air" but the native vertical range renders min at bottom on most browsers, causing directional ambiguity); no smooth fall animation — crown teleports based on slider value with no timed transition sequence.
Slider direction is inverted (min=0 at top maps to "in air" but the native vertical range renders min at bottom on most browsers, causing directional ambiguity); no smooth fall animation — crown teleports based on slider value with no timed transition sequence.