<!DOCTYPE html> <head> <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/KaTeX/0.3.0/katex.min.css"> <link rel="stylesheet" href="github-markdown.css"> <style> #input { display: block; font-size: 12pt; } #output { margin: 20px; } </style> </head> <body> <textarea id="input" type="textarea" rows=10, cols=80>$\sqrt{3x-1}+(1+x)^2$</textarea> <button id="button">Mathdown!</button> <div id="output" class="markdown-body"></div> <script src="./bundle.js"></script> </body>