The microformat buttons on the front page (and on other site pages) come from microformats.org's button page. (N.B.: I try to write semantically rich HTML when it makes sense to do so, and if you're using savvy software, such as Firefox with the Operator or Tails plug-ins, you should be able to make use of embedded information when browsing this site.)
The site's current styling is inspired by Skeleton; some pages use Skeleton directly for styling. There is a gradual transition happening that moves everything to Skeleton, but that will not be finished for a very long time, if ever.