✓ 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 at top maps to air, max=100 at bottom maps to water, which is nominally correct in intent, but the CSS uses writing-mode+direction:rtl causing the rendered top of the slider to be value=100/water, bottom=0/air — inverted UX); also the update() function is defined but never called (only updateFull runs), creating dead code, yet updateFull duplicates all logic correctly and the animation works well with physics, splash, bubbles, heureka, and comparison bars all properly implemented.
Slider direction is inverted (min=0 at top maps to air, max=100 at bottom maps to water, which is nominally correct in intent, but the CSS uses writing-mode+direction:rtl causing the rendered top of the slider to be value=100/water, bottom=0/air — inverted UX); also the update() function is defined but never called (only updateFull runs), creating dead code, yet updateFull duplicates all logic correctly and the animation works well with physics, splash, bubbles, heureka, and comparison bars all properly implemented.