Press the middle mouse button to autoscroll and, since the recent popup work, you got a flat grey square instead of the round double-arrow indicator. The autoscroll marker is itself a panel, so it was caught in the crossfire of FoxOne's popup styling.
Fixed
- The middle-click autoscroll indicator is round again, with its double-arrow glyph back. Firefox's
.autoscrolleris apanel, and toolkitglobal-shared.cssbuilds its entire look out of the very--panel-*tokens FoxOne overrides for every popup:--panel-border-radius: 100%draws the circle, and the double-arrow icon is baked into the--panel-background-colorvalue itself. All three popup blocks – colours, square corners, and the Mica opt-out – hit every panel with!important, so they flattened the circle to a square and painted over the arrow..autoscrolleris now excluded from all three, next to#DateTimePickerPanel, and falls back to its native styling.