This site's CSS takes 2796 bytes. This, however, does not include the following dependencies:
The minimal CSS is heavily inspired by 58 bytes of css to look great nearly everywhere.
The site is generated from a set of Markdown files using a Go pre-processor, which mainly converts the Mardown to HTML and gathers some metadata (such as gathering the backlinks for each page).
The generator also automatically detects whether a page includes mathematical notation, and if so, the proper dependencies are added.