✓ 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
Slider direction is inverted (min=0 at top maps to crowns in air, but vertical-lr + rtl with value=0 physically renders at bottom in most browsers, meaning "top of slider = water"); ASCII-art rendering is creative and physics values are accurate, but the text-based visualization limits animation realism.
Slider direction is inverted (min=0 at top maps to crowns in air, but vertical-lr + rtl with value=0 physically renders at bottom in most browsers, meaning "top of slider = water"); ASCII-art rendering is creative and physics values are accurate, but the text-based visualization limits animation realism.