Tab bar is fully transparent since the latest FF release.

[notarq]

I tried using opacity:1 !important on some .tabbrowser-tab selectors, but to no success.

Any pointers would be appreciated.

[notarq]

The workaround that worked for me

#titlebar {
	background-color: #solid-color !important;
}

[rockofox]

Hmm, I can't reproduce it on my setup. Could you tell me what OS and what Firefox Edition (Standard/Developer/Nightly) you're running? Maybe I can find a way to reproduce it

[notarq]

OS: Debian 12
Package: FF 119.0 (flatpak)

I don't think I have made any other modification, no user.js

Reproducible on fresh FF profile though.

Cheers and thanks! 👍