> How do you handle adding the same styles to page elements that aren't siblings/exist in vastly different areas of the dom structure?
That's usually a case for refactoring. Either by pulling styles common to both elements out and up the tree so they apply more widely or creating a class that can modify both. In the latter case we'll usually use a technique like the last example in the article (more of an OOCSS approach) that works independent of the dom structure.