Make the Document Bar "Back" button more visually distinguishable

[liviopv]

What problem does this address?

The "Back" button is displayed in the Document Bar when switching contexts like Page > Template, Patterns > Edit Original, Template Part in template > Edit is too easy to miss, since it's grey text over grey background.

It's easy to miss and might lead to users relying on the browser's back button, risking content loss.

What is your proposed solution?

This needs more design expertise than I can provide, but since it's already an element, the obvious option would be to make it look more like a button by adding a background, a border, or a different font color than the other elements in the Document Bar.

[stokesman]

There is at least one open issue for the Document Bar (#51460) but I don’t think it includes this specific point. I saw this today and it prompted me to make a PR for a branch I've had in the works for a bit #62527. It might not resolve the issue completely for you but it at least increases the contrast of the back button text (by way of a white background). Your opinion is welcome.