/* Setup styles are in the other file. */

div:nth-child(3) {
	background-color: gold;
	left: 30px;
	position: sticky;
	top: 30px;
	width: 66%;
}

div:nth-child(even) {
	position: relative;
	z-index: 1;
}
body {
	font-family: sans-serif;
	padding: 20px;
}

div {
	background-color: deepskyblue;
	border-top: solid black 4px;
	padding: 10px;
}

div:not(:first-child) { margin-top: 20px; }
<!DOCTYPE html>
<html>
	<head>
		<title>Z-index</title>
		<link href="/assets/styles/reset.css" rel="stylesheet">
		<link href="setup.css" rel="stylesheet">
		<link href="style.css" rel="stylesheet">
	</head>
	<body>
		<section>
			<div>
				<p>This is some text in the first element.</p>
			</div>
			<div>
				<p>And some more in the second element.</p>
			</div>
			<div>
				<p>Then a third one, too.</p>
			</div>
			<div>
				<p>Let’s add a fourth.</p>
			</div>
			<div>
				<p>Even a fifth.</p>
			</div>
			<div>
				<p>This should let it scroll.</p>
			</div>
			<div>
				<p>It was the best of times; it was the worst of times.</p>
			</div>
			<div>
				<p>Scrolling is always fun.</p>
			</div>
			<div>
				<p>I guess that isn’t true.</p>
			</div>
			<div>
				<p>Sometimes it goes on and on, you know.</p>
			</div>
			<div>
				<p>Okay, this is enough.</p>
			</div>
			<div>
				<p>Let’s make a longer scroll on this one.</p>
			</div>
			<div>
				<p>To really show off the stacking.</p>
			</div>
			<div>
				<p>One more, for good measure.</p>
			</div>
		</section>
	</body>
</html>