✓ 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
Physically coherent ASCII-tank demo with correct masses/densities and live displaced-water readout, but slider direction is inverted (value=0 is crowns in water, value=100 is crowns fully submerged), there are no fall/splash animations, mass/volume/density values are static text rather than live displays, and the slider is horizontal-only (writing-mode trick doesn't reliably produce a vertical slider).
Physically coherent ASCII-tank demo with correct masses/densities and live displaced-water readout, but slider direction is inverted (value=0 is crowns in water, value=100 is crowns fully submerged), there are no fall/splash animations, mass/volume/density values are static text rather than live displays, and the slider is horizontal-only (writing-mode trick doesn't reliably produce a vertical slider).