✓ 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 maps to crowns in air at top, value=100 to submerged, which is technically correct direction-wise, but the vertical slider widget with writing-mode/direction styling renders top=high-value/water, making the physical feel inverted for the user); ASCII art is creative but the crown-building logic has redundant/dead code paths and the water-rise scaling (0.04 rows/cm³) is arbitrary and not physically normalized to the tank dimensions.
Slider direction is inverted (value=0 maps to crowns in air at top, value=100 to submerged, which is technically correct direction-wise, but the vertical slider widget with writing-mode/direction styling renders top=high-value/water, making the physical feel inverted for the user); ASCII art is creative but the crown-building logic has redundant/dead code paths and the water-rise scaling (0.04 rows/cm³) is arbitrary and not physically normalized to the tank dimensions.