✓ 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 (min=0 at top maps to crowns in air, but the CSS uses writing-mode+direction rtl which visually flips the slider so dragging down increases value — functionally correct but semantically the slider label "▼ Ins Wasser" is at the bottom matching value=100, which is actually correct behavior, however the orient/appearance stack is ambiguous across browsers); physics values are solid (Gold 19.32 g/cm³, gilded 8.4 g/cm³, same 1000g mass, correct displaced volume scaling), Heureka overlay fires at sv≥98 with cycling ASCII frames and side-panel animation, but the ASCII crown art is identical for both crowns making visual distinction weak.
Slider direction is inverted (min=0 at top maps to crowns in air, but the CSS uses writing-mode+direction rtl which visually flips the slider so dragging down increases value — functionally correct but semantically the slider label "▼ Ins Wasser" is at the bottom matching value=100, which is actually correct behavior, however the orient/appearance stack is ambiguous across browsers); physics values are solid (Gold 19.32 g/cm³, gilded 8.4 g/cm³, same 1000g mass, correct displaced volume scaling), Heureka overlay fires at sv≥98 with cycling ASCII frames and side-panel animation, but the ASCII crown art is identical for both crowns making visual distinction weak.