You can tell something is
important by printing it
When each post in my blog is a separate page, I can vary the typography to suit the post, by changing the css for that page only.
It's not likely that I will bother with designing a separate stylesheet for each individual post. What I am planning to do is to have a collection of stylesheets, and then call the one most appropriate to whatever the post is about.
Let's say I want to post a couple of pictures. Then I could use a different layout than what I use for posts with only text.