Get Professionally Supported Material-UI
$ npm install @material-ui/core
<script src="https://unpkg.com/@material-ui/core/umd/material-ui.production.min.js" crossorigin="anonymous"></script>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500">
import React from 'react';
import Button from '@material-ui/core/Button';
const App = () => (
<Button variant="contained" color="primary">
Hello World
</Button>
);