section {
	display: flex;
	height: 120px;
	justify-content: space-between;
}

div:nth-child(1) {
	background-color: lightsalmon;
	flex-basis: 50%;
}
body {
	font-family: sans-serif;
	padding: 20px;
}

div {
	background-color: tomato;
	border-bottom: 2px solid firebrick;
	border-right: 2px solid firebrick;
	padding: 5px;
}

section {
	background-color: gold;
}

section:not(:first-child) {
	margin-top: 20px;
}
<!DOCTYPE html>
<html>
	<head>
		<meta name="viewport" content="width=device-width, initial-scale=1">
		<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>Item 1</p>
			</div>
			<div>
				<p>Item 2</p>
			</div>
			<div>
				<p>Item 3</p>
			</div>
		</section>
	</body>
</html>