✓ 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 (min=0/top=air is correct, but the vertical slider thumb starts at bottom when value=0, meaning the crown starts submerged in browsers using bt-lr writing-mode), mass/volume/density values are static HTML rather than live-updating span elements, and there is no smooth falling animation — crowns jump position directly with slider input.
Slider direction is inverted (min=0/top=air is correct, but the vertical slider thumb starts at bottom when value=0, meaning the crown starts submerged in browsers using bt-lr writing-mode), mass/volume/density values are static HTML rather than live-updating span elements, and there is no smooth falling animation — crowns jump position directly with slider input.