✓ 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
ASCII-art tank with two correctly-massed, different-density crowns and live physics panels is solid, but the crown rendering inside the tank is crude and barely visible, there is no true fall animation (crowns jump rather than fall), and the vertical slider uses the deprecated `writing-mode: bt-lr` / `-webkit-appearance: slider-vertical` approach which is broken in most modern browsers.
ASCII-art tank with two correctly-massed, different-density crowns and live physics panels is solid, but the crown rendering inside the tank is crude and barely visible, there is no true fall animation (crowns jump rather than fall), and the vertical slider uses the deprecated `writing-mode: bt-lr` / `-webkit-appearance: slider-vertical` approach which is broken in most modern browsers.