✓ 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 at top means air, value=100 means water, but the HTML vertical slider with writing-mode+direction:rtl renders high values at top visually, making it feel backwards to the user); otherwise an exceptionally polished, physics-accurate, feature-complete implementation with a stunning Heureka overlay, ripple/splash effects, live panel, and correct Archimedes values.
Slider direction is inverted (value=0 at top means air, value=100 means water, but the HTML vertical slider with writing-mode+direction:rtl renders high values at top visually, making it feel backwards to the user); otherwise an exceptionally polished, physics-accurate, feature-complete implementation with a stunning Heureka overlay, ripple/splash effects, live panel, and correct Archimedes values.