How can I force Opera to use the same window frame style, color, etc that I have in my System Settings (Kubuntu 18.04)?

By default Opera is using a minimalist frame where the standard buttons maximize, minimize, close,... appear fused in the tab bar and there are no edges for the window frame. This makes difficult to visually separate the different open windows when they overlap in the screen.

Thank you!

In new Opera One for Linux, the save/load-files window:

-Doesn't allow to type (or copy) the full path of a file when uploading. If you type "/", the search tool opens without any result, hindering the possibility of direct going to the file.

-Doesn't allow to rename the file when downloading. If you try to write over the "old name", the search tool appears again, difficulting the task (see attached image).

-Doesn't go to the last used directory, difficulting multiple downloads to the same directory (for example).

Thank you!

@lv44endershaman Thank you for answering! Hopefully we are a "silent majority"

How can I force Opera to use the same window frame style, color, etc that I have in my System Settings (Kubuntu 18.04)?

By default Opera is using a minimalist frame where the standard buttons maximize, minimize, close,... appear fused in the tab bar and there are no edges for the window frame. This makes difficult to visually separate the different open windows when they overlap in the screen.

Thank you!