✓ 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 (label says "Oben → Unten" but value=0 starts crowns in air at top and higher values push them down, which is nominally correct mechanically — however the slider's visual orientation via `writing-mode: bt-lr` means the physical thumb-up position corresponds to value=100/water, making the UX direction wrong for a vertical slider); displaced-water live value shows only the aggregate water-level rise in cm rather than a per-crown displaced volume in cm³, and the stat boxes show fixed values that don't update dynamically with submersion depth.
Slider direction is inverted (label says "Oben → Unten" but value=0 starts crowns in air at top and higher values push them down, which is nominally correct mechanically — however the slider's visual orientation via `writing-mode: bt-lr` means the physical thumb-up position corresponds to value=100/water, making the UX direction wrong for a vertical slider); displaced-water live value shows only the aggregate water-level rise in cm rather than a per-crown displaced volume in cm³, and the stat boxes show fixed values that don't update dynamically with submersion depth.