Highlight or border glow for inactive hidden windows that shows through on top of the window covering it

Help
1

I use KDE 6 on Debian 13 as my daily driver.

I’m looking for something and I’m not even sure what to search for to find it.

When I have multiple apps/windows open, and a window is hidden behind another window, I want some kind of persistent visual letting me know. I know I can do overview to show all windows, or add to taskbar, but that’s not what I want.

I’m thinking like some kind of glowing border that shows on top of the window covering the hidden window.

Any ideas?

2

Use a different window decorator. Try klassy.

3

Not following? The window in the back is completely hidden by the window in the front. So how would a different window decoration help?

4

O, you just want an indicator.

5

I want some kind of visual cue that there is a hidden window behind the current one.