body {
	font-family: sans-serif;
	padding: 1rem; /* An “inset” on the whole page. */
}

section {
	padding: 1rem; /* And again inside each of these. */

	/* Nesting with the `&` “parent” selector. */
	&:nth-child(1) { background-color: deepskyblue; }
	&:nth-child(2) { background-color: gold; }
	&:nth-child(3) { background-color: tomato; }
}