On the Models & Engines step at UI scale > 1, the pinned Continue button and HF-token card rendered below the window edge with no scrollbar to reach them. The sticky layout itself was correct — the wrap was a full-viewport box with a bare inline zoom on the mount, so the zoomed content overran the window by (1 − 1/scale). Invisible at scale 1, which is how it shipped through two earlier fixes.
Fix is the .app-container #504 contract: shrink the box to viewport ÷ scale, zoom back, plus the WebKitGTK zoom-no-op fallback; the mount passes --ui-scale as a CSS variable. Guarded in SetupWizardChrome.test.jsx (4 of 7 cases fail against the previous source) alongside the existing structural pins keeping Continue/HF-token outside the scroller.
Palash Debnath
fedb41ecbc