✓ 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, but sliding down increases value sending crowns into water — label says "FALLEN LASSEN ↓" at top and "STEIGEN LASSEN ↑" at bottom, which is backwards UX); ASCII-art rendering is functional but visually crude, and splash effects are stochastic/transient without persistence.
Slider direction is inverted (min=0 at top means crowns in air, but sliding down increases value sending crowns into water — label says "FALLEN LASSEN ↓" at top and "STEIGEN LASSEN ↑" at bottom, which is backwards UX); ASCII-art rendering is functional but visually crude, and splash effects are stochastic/transient without persistence.