✓ 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, but the vertical CSS writing-mode renders the slider so dragging down increases value — however the label says "ins Wasser eintauchen" and value 0=air/100=water which is logically correct top-to-bottom, yet the CSS `writing-mode: bt-lr` + `-webkit-appearance: slider-vertical` actually renders min at bottom and max at top, meaning top=water/bottom=air, which is inverted); also no distinct fall animation — crowns translate smoothly without a drop/impact event.
Slider direction is inverted (value=0/top = crowns in air is correct, but the vertical CSS writing-mode renders the slider so dragging down increases value — however the label says "ins Wasser eintauchen" and value 0=air/100=water which is logically correct top-to-bottom, yet the CSS `writing-mode: bt-lr` + `-webkit-appearance: slider-vertical` actually renders min at bottom and max at top, meaning top=water/bottom=air, which is inverted); also no distinct fall animation — crowns translate smoothly without a drop/impact event.