✓ 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 physics implementation (gold 19.3 g/cm³, gilded 13.0 g/cm³, same 1000 g mass, correct displacement ratio) with live panel values and Heureka fade-in, but crowns teleport to position rather than animating a fall, and the water-rise label exposes raw pixel values ("px") instead of a physical unit, slightly breaking immersion.
Solid physics implementation (gold 19.3 g/cm³, gilded 13.0 g/cm³, same 1000 g mass, correct displacement ratio) with live panel values and Heureka fade-in, but crowns teleport to position rather than animating a fall, and the water-rise label exposes raw pixel values ("px") instead of a physical unit, slightly breaking immersion.