ATAG Report Tool was approved to use a horizontal scroll bar for the nav bar when it doesn't fit in the viewport with the text size. Subsequent designs used that as well: ACT Rules, Supplemental Guidance, WCAG-EM Report Tool redesign, and WCAG upcoming.
Unfortunately:
the horizontal scrollbar doesn't appear by default in Chrome macOS (it does sometimes based on users settings)
the horizontal scrollbar is barely visible in Safari iOS
(EOWG participants can provide examples as useful)
ATAG Report Tool was approved to use a horizontal scroll bar for the nav bar when it doesn't fit in the viewport with the text size. Subsequent designs used that as well: ACT Rules, Supplemental Guidance, WCAG-EM Report Tool redesign, and WCAG upcoming.
Unfortunately:
(EOWG participants can provide examples as useful)