✓ 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 at top maps to crowns in air which is correct semantically, but the HTML slider with writing-mode/direction CSS renders min at bottom and max at top, making the physical direction ambiguous/browser-dependent); no true fall animation — crown position is only set by slider with no autonomous motion.
Slider direction is inverted (value=0 at top maps to crowns in air which is correct semantically, but the HTML slider with writing-mode/direction CSS renders min at bottom and max at top, making the physical direction ambiguous/browser-dependent); no true fall animation — crown position is only set by slider with no autonomous motion.