✓ 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 means crown in air at top, value=100 means submerged, but the slider rendered with writing-mode bt-lr means visually the bottom = 100 which is correct, however the appearance is browser-dependent and unreliable); no fall animation — crown teleports between positions rather than animating a fall; splash effect is random-noise-per-draw rather than a true event-triggered animation; physics values (densities, volumes, displaced water) are correct and coherent.
Slider direction is inverted (value=0 means crown in air at top, value=100 means submerged, but the slider rendered with writing-mode bt-lr means visually the bottom = 100 which is correct, however the appearance is browser-dependent and unreliable); no fall animation — crown teleports between positions rather than animating a fall; splash effect is random-noise-per-draw rather than a true event-triggered animation; physics values (densities, volumes, displaced water) are correct and coherent.