We would like the top header, left sidenav, and right sidebar to have true fixed positions so that the article text is the only content that moves when scrolling through the article. When I scroll down an article, the page header area scrolls out of view. The left sidenav menu and right sidebar (TOC + tags) also move in coordination with that change. We would like for article scrolling to have zero effect on the placement/position of the header, left sidnav, and right sidebar.