✓ 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 top=air/bottom=water but native vertical range input with min=0 maps thumb-up to value=0, which the code treats as "in air" — however the browser renders a vertical slider with min at bottom, so dragging up increases value and submerges the crown, making top=water, bottom=air visually); mass, volume, and density are static text, not live-updating values; no fall animation — crowns translate linearly without inertia or a distinct drop event.
Slider direction is inverted (label says top=air/bottom=water but native vertical range input with min=0 maps thumb-up to value=0, which the code treats as "in air" — however the browser renders a vertical slider with min at bottom, so dragging up increases value and submerges the crown, making top=water, bottom=air visually); mass, volume, and density are static text, not live-updating values; no fall animation — crowns translate linearly without inertia or a distinct drop event.