✓ 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 is top/air, value=100 is bottom/water which is correct for a range input, but writing-mode bt-lr means visually dragging up increases value, placing crowns deeper — needs verification; more critically, water height is calculated as a nonsensical fraction of 100 cm³ rather than true Archimedes displacement, and mass/volume/density values are static not live, with no fall animation between states.
Slider direction is inverted (value=0 is top/air, value=100 is bottom/water which is correct for a range input, but writing-mode bt-lr means visually dragging up increases value, placing crowns deeper — needs verification; more critically, water height is calculated as a nonsensical fraction of 100 cm³ rather than true Archimedes displacement, and mass/volume/density values are static not live, with no fall animation between states.