— 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
Entirely wrong demo: shows a generic Archimedes buoyancy explainer with a single red cube and button-driven animations — no crowns, no slider, no mass/volume/density/displaced-water readouts, and no Heureka moment as specified in the prompt.
Entirely wrong demo: shows a generic Archimedes buoyancy explainer with a single red cube and button-driven animations — no crowns, no slider, no mass/volume/density/displaced-water readouts, and no Heureka moment as specified in the prompt.