✓ 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
Solid Archimedes demo with correct physics (gold 19.3 g/cm³, alloy 13.0 g/cm³, same 1000 g mass), rising water levels, splash particles, and Heureka trigger at slider end — but crowns vanish rather than animate smoothly into water (the SVG crown is hidden and redrawn inline in the tank with no transition), making the "fall animation" effectively absent; slider direction is correct (top=air, bottom=submerged).
Solid Archimedes demo with correct physics (gold 19.3 g/cm³, alloy 13.0 g/cm³, same 1000 g mass), rising water levels, splash particles, and Heureka trigger at slider end — but crowns vanish rather than animate smoothly into water (the SVG crown is hidden and redrawn inline in the tank with no transition), making the "fall animation" effectively absent; slider direction is correct (top=air, bottom=submerged).