I'd like to set up a blog with different appearances for different kinds of posts, but I'm not sure how, or if it's even possible. As an example, I'd like short posts to show up as if they were mailed postcards, some longer posts as if they were magazine articles, others like journal pages.
How would I go about doing that? My first thought was to add a custom field and then do some CSS jiggery-pokery, but I'm not sure how to make the custom field give a property that CSS would recognize.