✓ 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 puts crowns in air at top, value=100 pushes them down, but the water level is incorrectly pegged to submersion percentage rather than actual displaced volume—both containers show identical water rise (both go from 0–100% at the same rate), negating the core Archimedes demonstration; mass/volume/density values are static labels not live-updating, and the crown visual never actually enters the water body since it sits above the water-level element.
Slider direction is inverted (value=0 puts crowns in air at top, value=100 pushes them down, but the water level is incorrectly pegged to submersion percentage rather than actual displaced volume—both containers show identical water rise (both go from 0–100% at the same rate), negating the core Archimedes demonstration; mass/volume/density values are static labels not live-updating, and the crown visual never actually enters the water body since it sits above the water-level element.