✓ 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 means crowns in air, slider dragged down increases value toward 100/water, which is actually correct directionally, but the label "OBEN" is at the bottom of the slider DOM and the crown rendering logic shows crowns in air at low slider values — functionally it works but the crown transition animation is absent; both crowns submerge identically so the key Archimedes insight (silver crown displaces more) is only visible in the numbers, not the visualization, and the water level rise scaling is arbitrary/non-physical.
Slider direction is inverted (min=0 at top means crowns in air, slider dragged down increases value toward 100/water, which is actually correct directionally, but the label "OBEN" is at the bottom of the slider DOM and the crown rendering logic shows crowns in air at low slider values — functionally it works but the crown transition animation is absent; both crowns submerge identically so the key Archimedes insight (silver crown displaces more) is only visible in the numbers, not the visualization, and the water level rise scaling is arbitrary/non-physical.