✓ 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 maps to crowns in air correctly, but the slider's native vertical rendering with writing-mode bt-lr means top of the thumb = high value = fully submerged, making bottom=air and top=water in practice); mass, volume, and density are static hardcoded labels rather than live reactive values; no fall animation (crown teleports via translateY with no easing).
Slider direction is inverted (value=0 at top maps to crowns in air correctly, but the slider's native vertical rendering with writing-mode bt-lr means top of the thumb = high value = fully submerged, making bottom=air and top=water in practice); mass, volume, and density are static hardcoded labels rather than live reactive values; no fall animation (crown teleports via translateY with no easing).