I’ve been working on a project where there are five sections for individual countries and each section has specific styling.
I was able to set the styling via css for the pages based on the page id and for categories based on the name of the category. I ran into a problem on the single post page, however, because there wasn’t a body class that could be used for single posts that are within a specific category. A single post has it’s post id but a client isn’t going to add each post id to the style sheet and that would be a ridiculous way to manage this.