@mdrights Last time I needed something like this, I found this repo https://github.com/dbohdan/classless-css

It has a lot of simple, nice looking #css themes with demos!

Although when you mean PDF export do you mean MD -> HTML -> PDF? Because when I've exported MD to PDF I usually go through #LaTeX. There are several packages for nice looking resumes on LaTeX, although most are rather inconvenient to setup...