✓ 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
Slider direction is inverted (value=0 at top means air, value=100 at bottom means submerged — label says correct but the water level rise logic is broken: `goldWaterLevel` is clamped to `Math.max(..., INITIAL_WATER_LEVEL)` which prevents it from ever rising, and the crown uses a single ASCII character rather than a real falling animation.
Slider direction is inverted (value=0 at top means air, value=100 at bottom means submerged — label says correct but the water level rise logic is broken: `goldWaterLevel` is clamped to `Math.max(..., INITIAL_WATER_LEVEL)` which prevents it from ever rising, and the crown uses a single ASCII character rather than a real falling animation.