This is the base Jekyll theme, with some minor modifications to support more complex math representations. I will write about my implementation at some point, though searching for how to use MathJax with Jekyll should be enough for experienced users. You can find out more info about customizing your Jekyll theme, as well as basic Jekyll usage documentation at jekyllrb.com

You can find the source code for Minima at GitHub: jekyll / minima

You can find the source code for Jekyll at GitHub: jekyll / jekyll