✓ 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
Comprehensive implementation with correct physics (ρ_gold=19.3, ρ_gilded=13.0, same 1000g mass), live data panels, splash particles, and Heureka animation, but lacks smooth fall animation (crowns teleport to position rather than animating independently) and the slider direction mapping (0%=air, 100%=water) is correct but the vertical slider top-to-bottom UX mapping may feel slightly unintuitive due to browser rendering of vertical range inputs.
Comprehensive implementation with correct physics (ρ_gold=19.3, ρ_gilded=13.0, same 1000g mass), live data panels, splash particles, and Heureka animation, but lacks smooth fall animation (crowns teleport to position rather than animating independently) and the slider direction mapping (0%=air, 100%=water) is correct but the vertical slider top-to-bottom UX mapping may feel slightly unintuitive due to browser rendering of vertical range inputs.