✓ 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 (slider-top = 0% = crowns in air is correct conceptually, but the vertical range input with writing-mode bt-lr means dragging up increases value, pushing crowns DOWN into water — directionally backwards); water level rise uses a geometrically inconsistent pixel-to-cm mapping, and buoyancy is not calculated from actual submerged depth but from an arbitrary progress fraction with different multipliers per crown, making the physics display misleading.
Slider direction is inverted (slider-top = 0% = crowns in air is correct conceptually, but the vertical range input with writing-mode bt-lr means dragging up increases value, pushing crowns DOWN into water — directionally backwards); water level rise uses a geometrically inconsistent pixel-to-cm mapping, and buoyancy is not calculated from actual submerged depth but from an arbitrary progress fraction with different multipliers per crown, making the physics display misleading.