JSFiddle - React, Tailwind, and code Playground

HTML

<body>
	<div class="menu_background">
	</div>
	<div id="wrapper">
		<nav>
			<a href="#">Home</a>
			<a href="#">Buy</a>
			<a href="#">Support</a>
			<a href="#">Development</a>			
		</nav>
	</div>
</body>

CSS

*{
	margin: 0;
	padding: 0;
}
#wrapper{
	width: 960px;
	height: 2500px;
	background: #ccc;
	margin: 0 auto;
	z-index: 2;
}
#wrapper nav a{
	color: #fff;
	padding: 15px;
	line-height: 30px;
}
.menu_background{
	position: fixed;
	height: 30px;
	width: 100%;
	background: #3a7c8c;
	z-index: 1;
}