<div class="container">
	<h1>Page title</h1>
	<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Reprehenderit, minima! Qui error expedita nesciunt voluptatibus quam eligendi aperiam odit officiis minus. Sit explicabo expedita labore vitae assumenda non adipisci sint!</p>
</div>
.container {
	width: 75%;
	margin: 2rem auto;
}

/* Default colors. */
body {
  	color: rgba(0, 0, 0, .85);
}

/* Dark mode styles. */
@media (prefers-color-scheme: dark) {
 	body {
    	color: rgba(255, 255, 255, .85);
    	background-color: rgba(0, 0, 0, .85);
  	}
}

External CSS

  1. https://codepen.io/tutsplus/pen/ZpvWBO

External JavaScript

This Pen doesn't use any external JavaScript resources.