✓ 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
Solid ASCII-art implementation covering all core requirements with correct physics (gold 19.3, alloy 13.0, same 1000g mass, proportional displacement), but the crown movement is driven by a polling loop rather than smooth interpolation, producing choppy motion, and there is no true fall animation — the slider linearly repositions crowns with no inertia or drop effect.
Solid ASCII-art implementation covering all core requirements with correct physics (gold 19.3, alloy 13.0, same 1000g mass, proportional displacement), but the crown movement is driven by a polling loop rather than smooth interpolation, producing choppy motion, and there is no true fall animation — the slider linearly repositions crowns with no inertia or drop effect.