✓ 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 (writing-mode bt-lr means dragging down increases value, but the label "Luft" is at top and "Wasser" at bottom yet the crown moves DOWN as value increases — visually consistent but the native slider thumb travels bottom-to-top for increasing values, making UX confusing); mass, volume, and density values are static rather than dynamically updated live values, and there is no animated fall sequence — crowns jump position instantly with slider movement rather than animating.
Slider direction is inverted (writing-mode bt-lr means dragging down increases value, but the label "Luft" is at top and "Wasser" at bottom yet the crown moves DOWN as value increases — visually consistent but the native slider thumb travels bottom-to-top for increasing values, making UX confusing); mass, volume, and density values are static rather than dynamically updated live values, and there is no animated fall sequence — crowns jump position instantly with slider movement rather than animating.