✓ 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 major features implemented cleanly in a single SVG/JS file with correct physics (gold 19.3 g/cm³, alloy 13.0 g/cm³, same 1000 g mass), but the slider is a custom SVG drag target rather than a native range input, which makes it somewhat fiddly, and mass/volume/density values are static labels rather than dynamically updating live values tied to slider state.
9,769 output tokens · claude-opus-4-6 · end_turn
All major features implemented cleanly in a single SVG/JS file with correct physics (gold 19.3 g/cm³, alloy 13.0 g/cm³, same 1000 g mass), but the slider is a custom SVG drag target rather than a native range input, which makes it somewhat fiddly, and mass/volume/density values are static labels rather than dynamically updating live values tied to slider state.