✓ 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 is inverted (value=0 at top → crowns in air is correct in appearance only because min=0 maps to the start position, but the writing-mode slider in most browsers has bottom=high value, so direction is likely inverted); displaced-water calculation uses a broken formula (waterLevel computed as 380 - depth*1.8 px, then compared to crown pixel positions directly, conflating pixels with cm³ in a physically nonsensical way) and the "silver" density of 7.4 g/cm³ is plausible for a silver-copper alloy but the water rise uses a capped arbitrary pixel formula rather than true Archimedes volume-to-area conversion.
Slider is inverted (value=0 at top → crowns in air is correct in appearance only because min=0 maps to the start position, but the writing-mode slider in most browsers has bottom=high value, so direction is likely inverted); displaced-water calculation uses a broken formula (waterLevel computed as 380 - depth*1.8 px, then compared to crown pixel positions directly, conflating pixels with cm³ in a physically nonsensical way) and the "silver" density of 7.4 g/cm³ is plausible for a silver-copper alloy but the water rise uses a capped arbitrary pixel formula rather than true Archimedes volume-to-area conversion.