<!doctype html>
<html>
	<head>
		<meta name="viewport" content="width=device-width, initial-scale=1">
		<link href="/assets/reset.css" rel="stylesheet">
		<link href="setup.css" rel="stylesheet">
		<link href="style.css" rel="stylesheet">
	</head>
	<body>
		<section>
			<h2>A heading</h2>
			<p>This is a paragraph, so we have some text to overflow our container. Another sentence, another line. It’s probably nearly long enough now, but I’m just getting in the groove of typing it out.</p>
		</section>
		<section>
			<h2>A heading</h2>
			<p>This is a paragraph, so we have some text to overflow our container. Another sentence, another line. It’s probably nearly long enough now, but I’m just getting in the groove of typing it out.</p>
		</section>
		<section>
			<h2>A heading</h2>
			<p>This is a paragraph, so we have some text to overflow our container. Another sentence, another line. It’s probably nearly long enough now, but I’m just getting in the groove of typing it out.</p>
		</section>
	</body>
</html>
index.html
			body {
	--base: 20px;

	display: grid;
	font-family: 'Helvetica', sans-serif;
	gap: var(--base);
	padding: var(--base);
}

section {
	background-color: gold;
	padding: calc(var(--base) / 2);
}

h2 { font-size: calc(var(--base) * 3); }
setup.css
			section { position: relative } /* For the `absolute`. */

section::after {
	color: white;
	content: 'Appears in front!'; /* Give us an element to work with. */
	inset: 2em;
	position: absolute;
	padding: 1em;
}

section:first-child::after {
	backdrop-filter: blur(8px); /* `blur` is a common use. */
	background-color: color-mix(in srgb, #333, transparent) /* Shade it. */
}

section:nth-child(2)::after {
	background-color: tomato;
	mix-blend-mode: multiply; /* Just like Photoshop/Figma! */
}

section:nth-child(3)::after {
	backdrop-filter: invert(1);
	background-color: deepskyblue;
	mix-blend-mode: multiply; /* You can do crazy combinations. */
}
style.css