✓ 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
Solid ASCII-art implementation with correct physics (gold 19.3 g/cm³, gilded 13.0 g/cm³, same 1000 g mass) and live data panel, but slider direction is inverted (value=0 at top maps to crown in air is correct per labels, yet the vertical-slider CSS with direction:rtl likely renders bottom=air/top=water depending on browser), and there is no smooth fall animation — crown teleports discretely with slider position rather than animating autonomously.
Solid ASCII-art implementation with correct physics (gold 19.3 g/cm³, gilded 13.0 g/cm³, same 1000 g mass) and live data panel, but slider direction is inverted (value=0 at top maps to crown in air is correct per labels, yet the vertical-slider CSS with direction:rtl likely renders bottom=air/top=water depending on browser), and there is no smooth fall animation — crown teleports discretely with slider position rather than animating autonomously.