After the update, most of my themeing broke so I just finished getting everything working again.
Distro: Fedora KDE Spin
WM: KWin
Global Theme: WhiteSur
Firefox Theme: WhiteSur
Start Page: NightTab
Minecraft Launcher: Prism Launcher
For this specific theme https://github.com/vinceliuice/WhiteSur-firefox-theme
Other themes https://firefoxcss-store.github.io/