Adjust Border Color Based on User Theme

[LSeelig]

From using the color picker, I am fairly certain Libadwaita uses
#c7c7c7 for the borders in light mode and #333333 on dark mode. If I try to make 1px borders of either of them, and then my theme switches (I have my system set to switch to dark mode at sunset), the coloring is wrong.

[pakovm-git]

Hello everyone, I guess this is not the exact place to upload how dynamic borders would look, but I don't think there a better place either.

I've been looking for a feature like this for a long time now, so I guess the best would be to show how it looks with my workarounds so the devs can have an idea of what some users might want:

I achieved a different border colour for focused windows by installing the Highlight Focus extension and disabling the hiding, now the problem, is that modal dialogs do not inhered this property when focused and moving windows do not display the coloured border but the native one from the Rounded Corners extension.

It would be great it we could get:

1. A border specifically made for focused windows.
2. A dynamic colour setting on that border thatsymply applies the accent colour of the system.

Again, I don't know if this is the right place for this, if it isn't I would gladly open a new feature request.

[flexagoon]

A border specifically made for focused window

@pakovm-git there's an open PR for that: #37