No CSS hook exists for distinguishing between content/history/etc actions for a given page title. This obviously prevents CSS from changing the appearance based on the action being performed.
This limitation appears to be inherent to all SkinTemplate.php derived skins, as I can see nothing in that code that references the action.
I was implementing a link highlighting suggestion made by Timwi in this WikiEN-l post: http://mail.wikimedia.org/pipermail/wikien-l/2005-October/031082.html
With the <body class="ns-0">, I was able to restrict the behavior to only the article namespace. However, I found no way to prevent the behavior from appearing on edit, history, protection, deletion, move, and watch/unwatch pages for a given title.