✓ 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 (label says ↑ Air / ↓ Water but dragging down increases t which lowers the crown, so top=air is technically correct in mapping but the visual affordance and the CSS rotation quirk make it feel backwards to the user); all physics values are plausible, heureka triggers cleanly, and the dual-canvas layout is polished.
8,640 output tokens · claude-opus-4-6 · end_turn
Slider direction is inverted (label says ↑ Air / ↓ Water but dragging down increases t which lowers the crown, so top=air is technically correct in mapping but the visual affordance and the CSS rotation quirk make it feel backwards to the user); all physics values are plausible, heureka triggers cleanly, and the dual-canvas layout is polished.