✓ 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
Physics and displaced-water values are correct (Au 19.3 g/cm³ / 51.8 cm³ vs. gilded 13.0 g/cm³ / 76.9 cm³, same 1000 g mass), but mass/volume/density are static labels rather than live-updating values, and there is no fall animation — the crown teleports rather than smoothly dropping.
Physics and displaced-water values are correct (Au 19.3 g/cm³ / 51.8 cm³ vs. gilded 13.0 g/cm³ / 76.9 cm³, same 1000 g mass), but mass/volume/density are static labels rather than live-updating values, and there is no fall animation — the crown teleports rather than smoothly dropping.