This theme supports rendering beautiful math in inline and display modes using KaTeX engine. You just need to surround your math expression with $$, like $$ E = mc^2 $$. If you leave it inside a paragraph, it will produce an inline expression, just like $E = mc^2$. To use display mode, again surround your expression with $$ and place it as a separate paragraph. Here is an example:

Note that KaTeX is work in progress, so it does not support the full range of math expressions as, say, MathJax. Yet, it is blazing fast.