✓ 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 horizontal (not vertical as required), and fall animation is absent — crown positions jump without easing; the displacement calculation logic has a subtle flaw (goldBottomY > waterLevel check inverts the expected condition for partially submerged crowns).
Slider is horizontal (not vertical as required), and fall animation is absent — crown positions jump without easing; the displacement calculation logic has a subtle flaw (goldBottomY > waterLevel check inverts the expected condition for partially submerged crowns).