✓ 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/top → crowns in air is correct in logic but the writing-mode bt-lr means dragging up increases value, yet the crown movement formula subtracts depth moving crowns upward rather than downward — crowns rise instead of fall as slider increases, violating the top=air/bottom=water convention); no smooth fall animation, crowns teleport proportionally with slider position.
Slider direction is inverted (value=0/top → crowns in air is correct in logic but the writing-mode bt-lr means dragging up increases value, yet the crown movement formula subtracts depth moving crowns upward rather than downward — crowns rise instead of fall as slider increases, violating the top=air/bottom=water convention); no smooth fall animation, crowns teleport proportionally with slider position.