✓ 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 vs alloy 13.0, same 1000 g mass), iterative water-level solver, and genuine splash particles, but crown movement is purely slider-driven with no autonomous fall animation — the "fall_animation" is just slider-coupled translation, not a timed drop sequence.
Solid Archimedes demo with correct physics (gold 19.3 g/cm³ vs alloy 13.0, same 1000 g mass), iterative water-level solver, and genuine splash particles, but crown movement is purely slider-driven with no autonomous fall animation — the "fall_animation" is just slider-coupled translation, not a timed drop sequence.