✓ 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 crowns in air, but native vertical range slider renders with 0 at bottom in most browsers, making bottom=air/top=water); water level visually does not rise despite displacement math — the waterBody height update is computed incorrectly (adds volume in cm³ directly to pixel height), so the visual rising is imperceptible or broken.
Slider direction is inverted (min=0 at top maps to crowns in air, but native vertical range slider renders with 0 at bottom in most browsers, making bottom=air/top=water); water level visually does not rise despite displacement math — the waterBody height update is computed incorrectly (adds volume in cm³ directly to pixel height), so the visual rising is imperceptible or broken.