✓ 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
Highly complete SVG-based demo with correct physics (Au 19.32, alloy 11.0 g/cm³, same 1000 g mass), working splash/heureka/wave animations, and clear displacement comparison, but the slider is a custom SVG drag handle (not a native range input) with no automated fall animation—crowns teleport rather than falling smoothly.
12,876 output tokens · claude-opus-4-6 · end_turn
Highly complete SVG-based demo with correct physics (Au 19.32, alloy 11.0 g/cm³, same 1000 g mass), working splash/heureka/wave animations, and clear displacement comparison, but the slider is a custom SVG drag handle (not a native range input) with no automated fall animation—crowns teleport rather than falling smoothly.