✓ 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 vs gilded 5.0 g/cm³, same 1000 g mass), live readouts, water rise, splash effects, and Heureka overlay all working, but the crown movement is instant per slider tick (no smooth fall animation) and ASCII rendering leaves the visual clarity of "gilded displaces more" dependent on reading numbers rather than striking visuals.
Solid ASCII-art implementation with correct physics (gold 19.3 g/cm³ vs gilded 5.0 g/cm³, same 1000 g mass), live readouts, water rise, splash effects, and Heureka overlay all working, but the crown movement is instant per slider tick (no smooth fall animation) and ASCII rendering leaves the visual clarity of "gilded displaces more" dependent on reading numbers rather than striking visuals.