JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
<math xmlns='http://www.w3.org/1998/Math/MathML' display='block'>
  <munderover>
    <mo>&sum;</mo>
    <mrow>
      <mi>n</mi>
      <mo>=</mo>
      <mn>0</mn>
    </mrow>
    <mi>k</mi>
  </munderover>
</math>

CSS

body {
      font-size: 2em;
    }