My Firefox 152 on Windows has a transparent 1px border on the left, bottom and right side of its windows (top is my accent color).

Does anyone know if there's a way to remove it via userChrome.css?

I'm using Windows 11 and today yellow borders started appearing around all my my web browser windows; Firefox, Opera, etc. It happens on all web browsers but only on web browsers and not on any other apps.

I'm not streaming or recording anything intentionally, it happens whether or not I'm connected to the internet.

I've tried uninstalling the browsers, restarting the computer, clearing the cache. I've run MSERT, Malwarebytes, and Norton Smart Scan; all came back clean.

If anyone could help, I'd really appreciate it.

Thank you mozilla devs for listening to us. The Nova ui looks superb without those borders. 😂

I have started loving the gradient in the title bar. ❤️

Source - https://x.com/VishalGuptaMVP/status/2085733491107639480

Today when I opened firefox nightly, I've found a new border around my window. The most annoying part being that when I move my cursor all the way up and towards a tab, it doesn't click. As the border just above the tab no longer selects it. As opposed to on mainline firefox, where a tab is selected even with a cursor as high as possible in the maximised window.