✓ 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 (value=0 places crowns at pixel y=500 near bottom/water, value=100 pushes them to y=0 at top/air — opposite of the required top=air, bottom=water UX); no smooth fall animation (crowns teleport instantly); splash triggers only at multiples of 10%, not on actual water-surface crossing.
Slider direction is inverted (value=0 places crowns at pixel y=500 near bottom/water, value=100 pushes them to y=0 at top/air — opposite of the required top=air, bottom=water UX); no smooth fall animation (crowns teleport instantly); splash triggers only at multiples of 10%, not on actual water-surface crossing.