JSFiddle - React, Tailwind, and code Playground
HTML
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>
<script src="http://manos.malihu.gr/tuts/custom-scrollbar-plugin/jquery.mousewheel.min.js"></script>
<script src="http://manos.malihu.gr/tuts/custom-scrollbar-plugin/jquery.mCustomScrollbar.js"></script>
<link rel="stylesheet" href="http://manos.malihu.gr/tuts/custom-scrollbar-plugin/demo_files/jquery.mCustomScrollbar.css">
<html>
<head>
<style>
body{background:red; color:#ddd;}
.content{width:250px; height:450px; overflow:auto; background: green;}
</style>
</head>
<body>
<div class="content">
<!-- your long content here... -->
<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content<br />Content
</div>
</body>
</html>
JavaScript
$(document).ready(function(){
$(".content").mCustomScrollbar();
});