Loading bar hard to see when browser theme doesn't match our theme #3086
Description
I thought we had introduced a problem in #3061 with the color of the loading bar, but it turns out that we actually already had a pretty big problem with the color of the loading bar, and I just didn't realize because my Firefox has dark UI chrome.
The loading bar is only visible properly when both the chrome and the page theme match. When one is dark and the other is light, the loading bar is lost visually somehow in boundary.
2026-02-23-loading-bar-light-chrome.mp4
2026-02-23-loading-bar-dark-chrome.mp4
Originally posted by @david-crespo in #3061 (comment)