✓ 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 (hint says "pull down" but the writing-mode+direction:rtl combo means slider top=water/bottom=air), and crowns jump instantly rather than animating a fall; otherwise physics, visuals, and live readouts are solid.
Slider direction is inverted (hint says "pull down" but the writing-mode+direction:rtl combo means slider top=water/bottom=air), and crowns jump instantly rather than animating a fall; otherwise physics, visuals, and live readouts are solid.