✓ 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
Both crowns move together as one unit rather than independently, water displacement logic is broken (submerge fraction calculation references a moving baseline making it nearly always zero), slider direction is inverted (value=0 puts crowns in air but min=0/max=100 with writing-mode bt-lr means top of slider = 0 = air, which visually inverts the expected mapping), and the "gilded displaces more" effect is not visually clear because displacement barely changes.
Both crowns move together as one unit rather than independently, water displacement logic is broken (submerge fraction calculation references a moving baseline making it nearly always zero), slider direction is inverted (value=0 puts crowns in air but min=0/max=100 with writing-mode bt-lr means top of slider = 0 = air, which visually inverts the expected mapping), and the "gilded displaces more" effect is not visually clear because displacement barely changes.