That thing usually goes by the name "wake lock". I can't imagine why it's not doing the right thing by default.
I use qtile on X11 and hyprland on Wayland. There is an option on hyprland for exactly that (idleinhibit window rule), but didn't find a good solution on qtile yet. Anyway I have issues with qtile for other things too (because of X11 mainly).
Try putting the browser on fullscreen, see if that keeps the screen alive while playing.
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
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