✓ 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/top = crowns in air, value=100/bottom = crowns in water maps correctly in logic, but the HTML vertical range renders with 0 at bottom and 100 at top in most browsers, making the physical direction feel backwards); all other features are robustly implemented with correct physics, polished visuals, and a satisfying Heureka overlay.
Slider direction is inverted (value=0/top = crowns in air, value=100/bottom = crowns in water maps correctly in logic, but the HTML vertical range renders with 0 at bottom and 100 at top in most browsers, making the physical direction feel backwards); all other features are robustly implemented with correct physics, polished visuals, and a satisfying Heureka overlay.