JSFiddle - React, Tailwind, and code Playground

HTML

<div id="top">
    <header>
        <hgroup>
            <h1>LOGO</h1>
        </hgroup>
        <nav>
	        <ul>
		        <li class="tabs"><a href="#">First</a></li>
		        <li class="tabs"><a href="#">Second</a></li>
			    <li class="tabs"><a href="#">Third</a></li>
		        <li class="tabs"><a href="#">Fourth</a></li>
            </ul>
       </nav>
    </header>

CSS

#top {
    background-color: #1b1b1b;
    box-shadow: 0px 0px 9px rgba(0,0,0,0.15);

	width: 100%;
    height: 70px;
    z-index: 99999;
    position: fixed;
    top: 0;
    left: 0;
}
header {
    position: relative;
    width: 100%;
    height: 70px;
    margin: 0 auto;
}
header hgroup {
    position: absolute;
    display: block;
    top: 5px;
    left: 20px;
}
header hgroup h1 {
	font-size: 50px;
    color: #fff;
    display: block;
    height: 100px;
    width: 610px;
}
nav {
	float: right;
}
nav ul li:hover > ul {
	display: block;
}
nav ul {
	margin-top: 10px;
	padding: 0 20px;  
	list-style: none;
	position: relative;
	display: inline-table;

}
nav ul:after {
	content: ""; 
	clear: both; 
	display: block;
}
nav ul li {
	float: left;
}
nav ul li:hover {
	color: #fff;
}
.tabs:hover {
    border-bottom: 5px solid #fff;
}
nav ul li a:hover {
	color: #fff;
}
nav ul li a {
	display: block; 
	padding: 15px 15px;		
    font-family: 'PT Sans', sans-serif;
	color: #fff; 
	text-decoration: none;
}