✓ 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 with correct physics (gold 19.32, gilded 10.5 g/cm³, same 1000 g mass), live panel values, splash triggers, and a glowing Heureka overlay, but the "fall animation" is purely slider-driven (no autonomous drop animation), the water-rise display is in abstract "row" units rather than cm, and the vertical slider uses browser-inconsistent -webkit-appearance hacks that may not render correctly on all platforms.
Solid ASCII-art implementation with correct physics (gold 19.32, gilded 10.5 g/cm³, same 1000 g mass), live panel values, splash triggers, and a glowing Heureka overlay, but the "fall animation" is purely slider-driven (no autonomous drop animation), the water-rise display is in abstract "row" units rather than cm, and the vertical slider uses browser-inconsistent -webkit-appearance hacks that may not render correctly on all platforms.