2023 rewrite

I highly recommend using these Firefox addons instead of this script, or just picture-in-picture ;-)
https://addons.mozilla.org/en-US/firefox/addon/maximize-video/
https://addons.mozilla.org/en-US/firefox/addon/popup-window/

should only work with these css stylesheets
https://greasyfork.org/en/scripts/462428-tele5-base-usercss-2023
+
https://greasyfork.org/en/scripts/440651-tele5-video-usercss-2023