✓ 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 (ρ_gold=19.3, ρ_fake=11.3, same 1000g mass), live data panels, SVG-animated splash/bubbles, elastic-eased Heureka overlay, and proportional water rise — main weakness is the slider being a custom SVG drag target (not a native range input) with a narrow 120px travel range that feels imprecise.
12,814 output tokens · claude-opus-4-6 · end_turn
Exceptionally complete implementation with correct physics (ρ_gold=19.3, ρ_fake=11.3, same 1000g mass), live data panels, SVG-animated splash/bubbles, elastic-eased Heureka overlay, and proportional water rise — main weakness is the slider being a custom SVG drag target (not a native range input) with a narrow 120px travel range that feels imprecise.