✓ 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/"Luft" at top label, but the HTML places "Luft" as the top label while increasing value moves crowns down toward water — the writing-mode vertical slider actually makes value=0 sit at the bottom in most browsers, so Luft/Wasser labels are swapped relative to actual slider behavior); mass, volume, and density values are hardcoded and non-live; crown submersion range is shallow (crowns barely reach the water surface even at slider=100), so full submersion is never truly achieved and Heureka rarely triggers.
Slider direction is inverted (min=0/"Luft" at top label, but the HTML places "Luft" as the top label while increasing value moves crowns down toward water — the writing-mode vertical slider actually makes value=0 sit at the bottom in most browsers, so Luft/Wasser labels are swapped relative to actual slider behavior); mass, volume, and density values are hardcoded and non-live; crown submersion range is shallow (crowns barely reach the water surface even at slider=100), so full submersion is never truly achieved and Heureka rarely triggers.