✓ 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 (min=0 at top maps to crowns in air but HTML range inputs render vertically with max at top in some browsers; more critically, crown Y increases with slider value meaning pushing slider down = crowns go down, which may be correct directionally, but the appearance attribute behavior is inconsistent cross-browser) and mass/volume/density values are static, not "live" in the sense they change — plus no fall animation, just instant repositioning.
Slider direction is inverted (min=0 at top maps to crowns in air but HTML range inputs render vertically with max at top in some browsers; more critically, crown Y increases with slider value meaning pushing slider down = crowns go down, which may be correct directionally, but the appearance attribute behavior is inconsistent cross-browser) and mass/volume/density values are static, not "live" in the sense they change — plus no fall animation, just instant repositioning.