✓ 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 required features are implemented correctly with solid physics (ρ_gold=19.3, ρ_alloy=13.0, same 1000g mass, proportionally larger displaced volume for gilded crown), but water-level rise indicators display "px" instead of a physically meaningful unit, and the ripple amplitude is overly subtle (0–3px).
All required features are implemented correctly with solid physics (ρ_gold=19.3, ρ_alloy=13.0, same 1000g mass, proportionally larger displaced volume for gilded crown), but water-level rise indicators display "px" instead of a physically meaningful unit, and the ripple amplitude is overly subtle (0–3px).