@wonghow why are you stating the obvious ? the point of the post is for the opera developers to add an option so the user can let the browser make use of the GTK theme. all the other browsers have this. you open chrome or firefox or whatever, they all have the option to use the gtk ( system ) theme. so far Opera is the only browser i encountered that has a god awful ugly linux border theme, its really terrible looking, like something made in wordpress in 1999.... if it was prettier it would be acceptable.

Also it is NOT using QT theme of the system, i am running KDE and my QT theme looks different to the opera theme.

and btw, even on windows opera uses its own theme, it looks similar to windows 11, but its not exact. so dont say its handled client side, its not.

@wonghow why are you stating the obvious ? the point of the post is for the opera developers to add an option so the user can let the browser make use of the GTK theme. all the other browsers have this. you open chrome or firefox or whatever, they all have the option to use the gtk ( system ) theme. so far Opera is the only browser i encountered that has a god awful ugly linux border theme, its really terrible looking, like something made in wordpress in 1999.... if it was prettier it would be acceptable.

Also it is NOT using QT theme of the system, i am running KDE and my QT theme looks different to the opera theme.

and btw, even on windows opera uses its own theme, it looks similar to windows 11, but its not exact. so dont say its handled client side, its not.

if the above image in original post doesnt work, here is a mirror.

https://yourimageshare.com/ib/FSlWSlhyDT

Linux Distro :
Debian, Ubuntu, any Linux distro, doesn't matter, I am currently using KDE 5.27.10 which is the latest one in the testing repos.

Your version of Opera :
108.0.5067.40

link to screenshot : https://ibb.co/Dt7YX0y

if you take a look at the screenshot, youll see other windows that are open and they all use the GTK window decorations, but then opera uses its own window decorations. seems there is no option on opera settings to make it use gtk theme ?

Why Why Why Why would you do this ? so now my desktop looks all nice and pretty and uniformed... all except this one app that looks ugly and doesnt share the same look as the rest of my system....

This is a deal breaker for me. Until this is fixed i cant use opera, im sorry, i tried it, it seems like a cool browser and all, but then this happens. ill keep an eye on this topic and if this problem is fixed at some point ill give it another go, but right now this is a deal breaker.