✓ 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 (0% = crowns in air at top maps correctly, but labeled "Hoch" at top / "Tief" at bottom yet crown Y moves down as slider increases — functionally correct direction but the water rise is identical in rate for both crowns, negating the key visual insight; mass/volume/density panels are static, not live; no fall animation, just an instant translate.
Slider direction is inverted (0% = crowns in air at top maps correctly, but labeled "Hoch" at top / "Tief" at bottom yet crown Y moves down as slider increases — functionally correct direction but the water rise is identical in rate for both crowns, negating the key visual insight; mass/volume/density panels are static, not live; no fall animation, just an instant translate.