✓ 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
Horizontal slider instead of required vertical slider, and slider direction is inverted (0=air, 100=water, but a vertical slider should have top=air/bottom=water); physics values are plausible (same mass 100g, gold 19.3 g/cm³ vs gilded 8.5 g/cm³), but the water-level rise from displaced volume is cosmetically negligible due to the pixel-scaling mismatch, and splash effects fire probabilistically throughout a range rather than only at water entry.
Horizontal slider instead of required vertical slider, and slider direction is inverted (0=air, 100=water, but a vertical slider should have top=air/bottom=water); physics values are plausible (same mass 100g, gold 19.3 g/cm³ vs gilded 8.5 g/cm³), but the water-level rise from displaced volume is cosmetically negligible due to the pixel-scaling mismatch, and splash effects fire probabilistically throughout a range rather than only at water entry.