✓ 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/top = crowns in air is correct in semantics, but writing-mode+direction CSS on the range input causes the physical top of the slider to correspond to max=100/water rather than min=0/air), and no smooth fall animation exists — crowns teleport proportionally with slider drag rather than playing an independent drop animation.
Slider direction is inverted (value=0/top = crowns in air is correct in semantics, but writing-mode+direction CSS on the range input causes the physical top of the slider to correspond to max=100/water rather than min=0/air), and no smooth fall animation exists — crowns teleport proportionally with slider drag rather than playing an independent drop animation.