✓ 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 maps to crowns in air, but the HTML labels "Luft" at top and "Wasser" at bottom with value=0 meaning air — however the crown Y logic maps frac=0 to crownTopAir and frac=1 to submerged, so top=air is actually correct, but the slider `direction: rtl` with vertical writing-mode means the physical thumb position is inverted: dragging down increases value correctly, yet the `orient=vertical` + `writing-mode: vertical-lr; direction: rtl` combo actually places max at top in most browsers, making top=water/frac=1 — direction is browser-dependent and unreliable); no smooth fall animation (crowns teleport per slider position rather than animating independently), and buoyancy force units are wrong (should be mN × 10 or expressed in N, since 1 cm³ water = 1g ≈ 9.81 mN but displaying ~508 mN for full gold submersion instead of ~508 mN which is actually correct for 51.8 cm³).
Slider direction is inverted (min=0 at top maps to crowns in air, but the HTML labels "Luft" at top and "Wasser" at bottom with value=0 meaning air — however the crown Y logic maps frac=0 to crownTopAir and frac=1 to submerged, so top=air is actually correct, but the slider `direction: rtl` with vertical writing-mode means the physical thumb position is inverted: dragging down increases value correctly, yet the `orient=vertical` + `writing-mode: vertical-lr; direction: rtl` combo actually places max at top in most browsers, making top=water/frac=1 — direction is browser-dependent and unreliable); no smooth fall animation (crowns teleport per slider position rather than animating independently), and buoyancy force units are wrong (should be mN × 10 or expressed in N, since 1 cm³ water = 1g ≈ 9.81 mN but displaying ~508 mN for full gold submersion instead of ~508 mN which is actually correct for 51.8 cm³).