JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://bootswatch.com/flatly/bootstrap.css">
<link rel="stylesheet" href="http://bootswatch.com/bower_components/font-awesome/css/font-awesome.min.css">
<link rel="stylesheet" href="http://bootswatch.com/assets/css/bootswatch.min.css">
<div class="navbar navbar-default navbar-fixed-top">
    <div class="container">
        <div class="navbar-header"> <a class="navbar-brand" href="./">Bootswatch</a>

            <button data-target="#navbar-main" data-toggle="collapse" type="button" class="navbar-toggle"> <span class="icon-bar"></span>
 <span class="icon-bar"></span>
 <span class="icon-bar"></span>

            </button>
        </div>
        <div id="navbar-main" class="navbar-collapse collapse">
            <ul class="nav navbar-nav">
                <li class="dropdown"> <a id="themes" href="#" data-toggle="dropdown" class="dropdown-toggle">Themes <span class="caret"></span></a>

                    <ul aria-labelledby="themes" class="dropdown-menu">
                        <li><a href="./default/">Default</a>
                        </li>
                        <li class="divider"></li>
                        <li><a href="./amelia/">Amelia</a>
                        </li>
                        <li><a href="./cerulean/">Cerulean</a>
                        </li>
                        <li><a href="./cosmo/">Cosmo</a>
                        </li>
                        <li><a href="./cyborg/">Cyborg</a>
                        </li>
                        <li><a href="./darkly/">Darkly</a>
                        </li>
                        <li><a href="./flatly/">Flatly</a>
                        </li>
                        <li><a href="./journal/">Journal</a>
                        </li>
                        <li><a href="./lumen/">Lumen</a>
                        </li>
                        <li><a href="./readable/">Readable</a>
                        </li>
                        <li><a...

JavaScript

$(".dropdown").hover(function () {
    $(this).addClass("open");
}, function () {
    $(this).removeClass("open");
});