✓ 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
Exceptionally complete implementation with correct physics (gold ρ=19.32, silver ρ=10.5, same 1000g mass), smooth wave/splash/confetti effects, and all live values updating — minor UX flaw is the slider drives a `t` variable but has no built-in easing on the crown fall transition boundary, making rapid slider movement feel slightly jerky at t≈0.35.
Exceptionally complete implementation with correct physics (gold ρ=19.32, silver ρ=10.5, same 1000g mass), smooth wave/splash/confetti effects, and all live values updating — minor UX flaw is the slider drives a `t` variable but has no built-in easing on the crown fall transition boundary, making rapid slider movement feel slightly jerky at t≈0.35.