<div>
	<details open>
		<summary>
			How do you create an accordion?
		</summary>
		<div>
			Easy! As long as you don't have to support IE11 or older browsers you could use <code>&lt;details&gt;</code> and <code>&lt;summary&gt;</code> natively.
		</div>
	</details>
	<details>
		<summary>
			What if I have to support IE11 or older browsers?
		</summary>
		<div>
			No worries. The fallback for these elements is quite good. They will display as open. You won't get the open/close mechanism, but you won't lose any content either.
		</div>
	</details>
	<details>
		<summary>
			What type of content can I have inside one of these?
		</summary>
		<div>
			Almost anything you'd like. The <code>&lt;details&gt;</code> element allows all <a href="https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Content_categories#flow_content" target="_blank">flow content</a>, which is basically everything.
		</div>
	</details>
	<details>
		<summary>
			How does it work?
		</summary>
		<div>
			The <code>&lt;details&gt;</code> element encapsulates the <code>&lt;summary&gt;</code> element. The <code>&lt;summary&gt;</code> becomes the 'label' for the <code>&lt;details&gt;</code> and acts like a button. When clicked, the attribute <code>open</code> is added to the <code>&lt;details&gt;</code> element, making it display. You can therefore style the open and closed states seperately if you'd like.
		</div>
	</details>
</div>
@import url('https://fonts.googleapis.com/css2?family=Inter:[email protected];400;500;600;700;800;900&display=swap');

*, *:after, *:before {
	box-sizing: border-box;
}

:root {
	font-size: 16px;
}

body {
	font-family: "Inter", sans-serif;
	line-height: 1.5;
	min-height: 100vh;
	font-size: 1.25rem;
}

*:focus {
	outline: none;
}

body > div {
	width: 90%;
	max-width: 600px;
	margin-left: auto;
	margin-right: auto;
	margin-top: 5rem;
	margin-bottom: 5rem;
}

details div {
	border-left: 2px solid #000;
	border-right: 2px solid #000;
	border-bottom: 2px solid #000;
	padding: 1.5em;
}

details div > * + * {
	margin-top: 1.5em;
}

details + details {
	margin-top: .5rem;
}

summary {
	list-style: none;
}

summary::-webkit-details-marker {
	display: none;
}

summary {
	border: 2px solid #000;
	padding: .75em 1em;
	cursor: pointer;
	position: relative;
	padding-left: calc(1.75rem + .75rem + .75rem);
}

summary:before {
	position: absolute;
	top: 50%;
	transform: translateY(-50%);
	left: .75rem;
	content: "↓";
	width: 1.75rem;
	height: 1.75rem;
	background-color: #000;
	color: #FFF;
	display: inline-flex;
	justify-content: center;
	align-items: center;
	flex-shrink: 0;
}

details[open] summary {
	background-color: #eee;
}

details[open] summary:before {
	content: "↑";
}

summary:hover {
	background-color: #eee;
}

a {
	color: inherit;
	font-weight: 600;
	text-decoration: none;
	box-shadow: 0 1px 0 0;
}

a:hover {
	box-shadow: 0 3px 0 0;
}

code {
	font-family: monospace;
	font-weight: 600;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

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