✓ 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 SVG-based implementation covering all required features; the slider is a custom SVG drag handle (not a native range input) but works well, direction is correct (top=air, bottom=water), physics values are accurate (Au 19.3 g/cm³, alloy 13.0 g/cm³, same 1000 g mass), and the Heureka animation, splash particles, rising water levels, and difference indicator all function correctly — minor weakness is that the slider drag area is slightly narrow and mass/density values are static (not dynamically recomputed per frame, just pre-set), but they are physically plausible and consistent.
9,722 output tokens · claude-opus-4-6 · end_turn
Exceptionally complete SVG-based implementation covering all required features; the slider is a custom SVG drag handle (not a native range input) but works well, direction is correct (top=air, bottom=water), physics values are accurate (Au 19.3 g/cm³, alloy 13.0 g/cm³, same 1000 g mass), and the Heureka animation, splash particles, rising water levels, and difference indicator all function correctly — minor weakness is that the slider drag area is slightly narrow and mass/density values are static (not dynamically recomputed per frame, just pre-set), but they are physically plausible and consistent.