✓ 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 prompt requirements fully implemented with correct physics (ρ_gold=19.32, ρ_fake=11.30, same 1000g mass), polished SVG visuals, splash/ripple effects, live data panels, comparison box, and an elaborate Heureka overlay; minor flaw is the custom SVG slider (no native range input) whose drag UX can feel imprecise on high-DPI or scaled viewports.
14,297 output tokens · claude-opus-4-6 · end_turn
All prompt requirements fully implemented with correct physics (ρ_gold=19.32, ρ_fake=11.30, same 1000g mass), polished SVG visuals, splash/ripple effects, live data panels, comparison box, and an elaborate Heureka overlay; minor flaw is the custom SVG slider (no native range input) whose drag UX can feel imprecise on high-DPI or scaled viewports.