✓ 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 maps to top/air but HTML range min=0 renders at bottom on vertical sliders, and the label layout places LUFT at top and WASSER at bottom contradicting the bt-lr writing-mode mapping); crown animation is a static ASCII symbol repositioned per frame with no fall physics, and the water-rise calculation uses a fixed divisor (51.8) rather than container cross-section, making it cosmetically approximate rather than rigorously derived.
Slider direction is inverted (value=0 maps to top/air but HTML range min=0 renders at bottom on vertical sliders, and the label layout places LUFT at top and WASSER at bottom contradicting the bt-lr writing-mode mapping); crown animation is a static ASCII symbol repositioned per frame with no fall physics, and the water-rise calculation uses a fixed divisor (51.8) rather than container cross-section, making it cosmetically approximate rather than rigorously derived.