[![top bar is visible through 'welcome back' message][1]][1] `.top-bar { z-index: 5050; }` versus `#overlay-header { z-index: 5052; }` so the overlay should win. Strangely enough disabling the top bar z-index fixes the issue. Another fix is to set the overlay background alpha to 1 instead of 0.95 So maybe a combination of the z-index and alpha is responsible for this? Using Firefox 67.0.1 on Windows 10. [1]: https://i.sstatic.net/Tjp7O.png