✓ 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 maps crowns high/in-air via the waterSurface calculation but the label says "sink into water ⬇" and the vertical slider's bottom physically reads as max due to bt-lr writing-mode inconsistency); water level does not visibly rise continuously with submersion depth — it only snaps when crowns cross the threshold; buoyancy force is divided by 100 without physical justification, making displayed Newton values wrong; ASCII-art rendering is creative but crowns share identical Y positions, giving no meaningful visual difference between displacement events.
Slider direction is inverted (value=0 maps crowns high/in-air via the waterSurface calculation but the label says "sink into water ⬇" and the vertical slider's bottom physically reads as max due to bt-lr writing-mode inconsistency); water level does not visibly rise continuously with submersion depth — it only snaps when crowns cross the threshold; buoyancy force is divided by 100 without physical justification, making displayed Newton values wrong; ASCII-art rendering is creative but crowns share identical Y positions, giving no meaningful visual difference between displacement events.