✓ 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 (value=0/top = crowns in air, value=100/bottom = crowns in water maps correctly in logic but the vertical CSS uses writing-mode+direction:rtl which makes the physical top of the slider the HIGH value, meaning dragging up submerges — opposite of the expected UX convention); all other features are well-implemented with correct Archimedes physics, polished canvas rendering, splash particles, and a proper Heureka modal.
Slider direction is inverted (value=0/top = crowns in air, value=100/bottom = crowns in water maps correctly in logic but the vertical CSS uses writing-mode+direction:rtl which makes the physical top of the slider the HIGH value, meaning dragging up submerges — opposite of the expected UX convention); all other features are well-implemented with correct Archimedes physics, polished canvas rendering, splash particles, and a proper Heureka modal.