Haha, it's fine, glad it worked out! What I actually meant was that linking to the wiki where it wasn't working, since it helps to see what code you're trying to use and find out the issue. :)
In this case, h5 and h6 type selectors alone aren't specific enough to override the default font size styling, while adding WikiaArticle class adds to specificity and hence let your styling work. It can be a headache, indeed!