✓ 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 (value=0 starts crowns at top of tank, sliding up increases depth instead of top=air/bottom=water), mass/volume/density values are static (not live), and fall animation is absent — crowns teleport rather than fall.
Slider direction is inverted (value=0 starts crowns at top of tank, sliding up increases depth instead of top=air/bottom=water), mass/volume/density values are static (not live), and fall animation is absent — crowns teleport rather than fall.