✓ 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
Impressively complete SVG-only implementation with correct physics (ρ_gold=19.3, ρ_alloy=13.0, equal mass=1000g), live data panels, splash/ripple particles, and Heureka fade-in — minor flaw: submersion fraction ignores rising water level feedback loop, and the slider handle transform uses a relative translate that could drift, but functionally solid throughout.
10,981 output tokens · claude-opus-4-6 · end_turn
Impressively complete SVG-only implementation with correct physics (ρ_gold=19.3, ρ_alloy=13.0, equal mass=1000g), live data panels, splash/ripple particles, and Heureka fade-in — minor flaw: submersion fraction ignores rising water level feedback loop, and the slider handle transform uses a relative translate that could drift, but functionally solid throughout.