✓ 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 at top = air, value=100 at bottom = water maps correctly in code, but the HTML range input with writing-mode/rtl/slider-vertical renders visually inverted on most browsers — top of slider physically produces low values, meaning dragging down increases immersion which is correct, BUT the label layout says "☁️ Luft" at top and "💧 Wasser" at bottom which actually matches; however the `orient=vertical` + `direction:rtl` combo typically inverts default browser behavior making top=100 and bottom=0, so the crown goes INTO water when slider is at top — needs verification, flagged as incorrect); physics values (gold 19.3 g/cm³, gilded 8.4 g/cm³, same 500g mass) are sound and buoyancy force calculation is plausible; heureka overlay with animation is well-executed; visual polish is high with gradients, jewels, wave animations, and force arrows.
Slider direction is inverted (value=0 at top = air, value=100 at bottom = water maps correctly in code, but the HTML range input with writing-mode/rtl/slider-vertical renders visually inverted on most browsers — top of slider physically produces low values, meaning dragging down increases immersion which is correct, BUT the label layout says "☁️ Luft" at top and "💧 Wasser" at bottom which actually matches; however the `orient=vertical` + `direction:rtl` combo typically inverts default browser behavior making top=100 and bottom=0, so the crown goes INTO water when slider is at top — needs verification, flagged as incorrect); physics values (gold 19.3 g/cm³, gilded 8.4 g/cm³, same 500g mass) are sound and buoyancy force calculation is plausible; heureka overlay with animation is well-executed; visual polish is high with gradients, jewels, wave animations, and force arrows.