✓ 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 present and physically correct (gold ρ=19.3, gilded ρ=13.0, same 1000 g mass, proper Archimedes buoyancy formula); crown SVG fades then redraws on canvas as it submerges, but the dual-rendering handoff is visually awkward and the water-rise label uses raw pixel values rather than meaningful physical units.
All required features present and physically correct (gold ρ=19.3, gilded ρ=13.0, same 1000 g mass, proper Archimedes buoyancy formula); crown SVG fades then redraws on canvas as it submerges, but the dual-rendering handoff is visually awkward and the water-rise label uses raw pixel values rather than meaningful physical units.