✓ 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 implemented with correct physics (gold 19.3 g/cm³, fake 5.5 g/cm³, same 300g mass), visually distinct crown sizes, live info panels, rising water, splash, and Heureka overlay; minor flaw is that the fake crown density 5.5 g/cm³ is labeled as "lead/gold mix" but is lower than lead (11.3), and buoyancy arrow scaling uses inconsistent multipliers between the two crowns.
All required features implemented with correct physics (gold 19.3 g/cm³, fake 5.5 g/cm³, same 300g mass), visually distinct crown sizes, live info panels, rising water, splash, and Heureka overlay; minor flaw is that the fake crown density 5.5 g/cm³ is labeled as "lead/gold mix" but is lower than lead (11.3), and buoyancy arrow scaling uses inconsistent multipliers between the two crowns.