✓ 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 21 required features are implemented with physically plausible values (gold 19.3 g/cm³, gilded 13.0 g/cm³, same 1000 g mass, correct displaced-volume difference); the iterative water-rise solver is a notable engineering touch, though the pixel-to-cm³ scale (PX_PER_CM3=0.9) is aesthetic rather than derived from container geometry, and the heureka text animates from an offscreen y=550 which flickers briefly before the SVG clips it.
All 21 required features are implemented with physically plausible values (gold 19.3 g/cm³, gilded 13.0 g/cm³, same 1000 g mass, correct displaced-volume difference); the iterative water-rise solver is a notable engineering touch, though the pixel-to-cm³ scale (PX_PER_CM3=0.9) is aesthetic rather than derived from container geometry, and the heureka text animates from an offscreen y=550 which flickers briefly before the SVG clips it.