Better Active Area Highlighting

Edit #2 - interactive mockup! codepen.io/Aeraglyx/full/yLXLYjX

Blender is very context dependent, so it's important to know which area is active . E.g. when you want to type in the Python Console or mute a node instead of moving to collection...

Currently we have a hard-coded header highlighting ( more like darkening of inactive, it seems Already fixed, thanks Pablo ), which makes it difficult to theme (and in some editors, header and "footer" are linked, but one is darkened) and often isn't that visible.

I think it could be beneficial to have an outline around the whole active area and get rid of the header "highlighting" (exaggerated for visibility here).

It could be more subtle ( go fullscreen ), the colour needs to be customizable.

The setting would be located in Themes > User Interface > Styles , just below Editor Outline .

Edit #1 - I was trying to figure out whether the border should take the full outline width or be thinner, but as noted by -L0Lock- , a lot can be borrowed from 3.0's area-joining functionality.

I also found a design task that acknowledges the issue - developer.blender.org/T68830 , maybe 3.0 would be a good time to tackle this since there are more UI changes planned?

And lastly, there are some inconsistencies regarding the editor outline width, it would be nice if the gaps were the same everywhere.

Thanks!