✓ 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
All required features are implemented with correct physics (iterative submerged-fraction solver, proper buoyancy in N, mass=1000g for both crowns, densities 19.3 vs 13.0), but the crown SVG disappears into the crown-area div and is redrawn via canvas when submerged, causing a visual seam/pop rather than a seamless continuous fall into the tank.
All required features are implemented with correct physics (iterative submerged-fraction solver, proper buoyancy in N, mass=1000g for both crowns, densities 19.3 vs 13.0), but the crown SVG disappears into the crown-area div and is redrawn via canvas when submerged, causing a visual seam/pop rather than a seamless continuous fall into the tank.