✓ 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 labeled "IN DER LUFT" at top but slider min=0 maps to crowns in air, which is actually correct in label but the slider's native vertical rendering with writing-mode bt-lr means dragging up increases value, making "IN DER LUFT" the bottom label visually — borderline); mass/volume/density values are static (not live), only displaced water updates live; no smooth fall animation (transform jumps without transition); splash particles fire at wrong position (top of container instead of water surface).
Slider direction is inverted (value=0 is labeled "IN DER LUFT" at top but slider min=0 maps to crowns in air, which is actually correct in label but the slider's native vertical rendering with writing-mode bt-lr means dragging up increases value, making "IN DER LUFT" the bottom label visually — borderline); mass/volume/density values are static (not live), only displaced water updates live; no smooth fall animation (transform jumps without transition); splash particles fire at wrong position (top of container instead of water surface).