✓ 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 means crowns in air, but the HTML writing-mode/rtl CSS causes the physical top of the slider to render as "Wasser" visually); physics values are accurate (gold 19.32 g/cm³, gilded 3.7 g/cm³, same 1000 g mass), but both crowns submerge at identical rates rather than showing any buoyancy difference in behavior.
Slider direction is inverted (value=0 at top means crowns in air, but the HTML writing-mode/rtl CSS causes the physical top of the slider to render as "Wasser" visually); physics values are accurate (gold 19.32 g/cm³, gilded 3.7 g/cm³, same 1000 g mass), but both crowns submerge at identical rates rather than showing any buoyancy difference in behavior.