✓ 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
Comprehensive SVG-only implementation with correct physics (1000 g same mass, 19.3 vs 13.0 g/cm³), live values, splash particles, wave animation, and Heureka reveal — but the slider is a custom SVG drag target (not a native range input), mass/density values are static rather than truly live, and the water-rise scale factor (0.30 px/cm³) is arbitrary rather than geometrically derived.
9,709 output tokens · claude-opus-4-6 · end_turn
Comprehensive SVG-only implementation with correct physics (1000 g same mass, 19.3 vs 13.0 g/cm³), live values, splash particles, wave animation, and Heureka reveal — but the slider is a custom SVG drag target (not a native range input), mass/density values are static rather than truly live, and the water-rise scale factor (0.30 px/cm³) is arbitrary rather than geometrically derived.