✓ 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 "Luft" at top/min=0 and "Wasser" at bottom/max=100, but with writing-mode:vertical-lr + direction:rtl the physical top of the slider corresponds to max=100/water, so dragging down moves crowns up — not matching the labeling intent); no true fall animation (crowns jump/interpolate position on slider drag rather than animating autonomously); physics values and displaced-water differential are accurate and clearly displayed; heureka overlay is well-implemented with pulsing ASCII art.
Slider direction is inverted (label says "Luft" at top/min=0 and "Wasser" at bottom/max=100, but with writing-mode:vertical-lr + direction:rtl the physical top of the slider corresponds to max=100/water, so dragging down moves crowns up — not matching the labeling intent); no true fall animation (crowns jump/interpolate position on slider drag rather than animating autonomously); physics values and displaced-water differential are accurate and clearly displayed; heureka overlay is well-implemented with pulsing ASCII art.