✓ 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 (min=0 at top maps to air, but the vertical CSS uses writing-mode/rtl causing the thumb-top position to equal value=100/water), and crown movement is driven by a requestAnimationFrame loop with no easing/fall animation — the crown teleports instantly with slider input rather than animating a fall.
Slider direction is inverted (min=0 at top maps to air, but the vertical CSS uses writing-mode/rtl causing the thumb-top position to equal value=100/water), and crown movement is driven by a requestAnimationFrame loop with no easing/fall animation — the crown teleports instantly with slider input rather than animating a fall.