✓ 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 required features are implemented 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 rather than a native input, the immersion fraction logic uses a fixed BASE_WATER_Y rather than tracking the rising waterline for the crown-top check (minor physics approximation), and the pulsating Heureka uses a non-origin-centered scale transform that causes jitter.
10,586 output tokens · claude-opus-4-6 · end_turn
All required features are implemented 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 rather than a native input, the immersion fraction logic uses a fixed BASE_WATER_Y rather than tracking the rising waterline for the crown-top check (minor physics approximation), and the pulsating Heureka uses a non-origin-centered scale transform that causes jitter.