✓ 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 top = crowns in air is correct structurally, but the CSS uses writing-mode+direction:rtl on a vertical slider making the physical top of the slider correspond to value=100/water, not value=0/air), and the splash effect is purely positional/static rather than truly animated, but otherwise this is a rich, well-structured implementation with correct physics (gold 19.3 g/cm³, gilded 6.0 g/cm³, same 1000 g mass), live panel values, buoyancy force display, a polished heureka overlay with particle burst, and clean German-language UI.
Slider direction is inverted (value=0 at top = crowns in air is correct structurally, but the CSS uses writing-mode+direction:rtl on a vertical slider making the physical top of the slider correspond to value=100/water, not value=0/air), and the splash effect is purely positional/static rather than truly animated, but otherwise this is a rich, well-structured implementation with correct physics (gold 19.3 g/cm³, gilded 6.0 g/cm³, same 1000 g mass), live panel values, buoyancy force display, a polished heureka overlay with particle burst, and clean German-language UI.