Markdown headings do not render properly

[joseph-x-li]

Headings in markdown format are way too small. For example, the words "About" and "Gallery" should be <h2>, but they are the size of normal text.

Here is a link to the live site: LINK

[joseph-x-li]

I was overriding layouts/_default/single.html with an old version of the file. Updating it with the new version fixes it.