Hello,

From designer point of view it should be enough to work with following CSS classes:

.PageManagerInfoContainer

.PageManagerInfo

You have control over enwrapping div and text's span elements, so you are able to give them look and feel as per your needs.

You can add their definitions, as you correctly mentioned, to following stylesheet:

~\App_Themes\Default\DesignMode.css

In case you want to be 100% sure you don't override those styles, you can add them to your main site stylesheet.

Best regards
Ondrej Vasil