Pen Settings

HTML

About HTML Preprocessors

HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

Learn more · Versions

Adding Classes

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. So you don't have access to higher-up elements like the <html> tag. If you want to add classes there that can affect the whole document, this is the place to do it.

About the <head>

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. If you need things in the <head> of the document, put that code here.

!
Insecure Resource

The resource you are linking to is using the 'http' protocol, which may not work when the browser is using https.

CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

Learn more · Versions

CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

We offer two popular choices: Autoprefixer (which processes your CSS server-side) and -prefix-free (which applies prefixes via a script, client-side).

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

Powered by Algolia
About External Resources

You can apply CSS to your Pen from any stylesheet on the web. Just put a URL to it here and we'll apply it, in the order you have them, before the CSS in the Pen itself.

You can also link to another Pen here (use the .css URL Extension) and we'll pull the CSS from that Pen and include it. If it's using a matching preprocessor, use the appropriate URL Extension and we'll combine the code before preprocessing, so you can use the linked Pen as a true dependency.

Learn more

+ add another resource

JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

Learn more · Versions

Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

Powered by Algolia
About External Resources

You can apply a script from anywhere on the web to your Pen. Just put a URL to it here and we'll add it, in the order you have them, before the JavaScript in the Pen itself.

If the script you link to has the file extension of a preprocessor, we'll attempt to process it before applying.

You can also link to another Pen here, and we'll pull the JavaScript from that Pen and include it. If it's using a matching preprocessor, we'll combine the code before preprocessing, so you can use the linked Pen as a true dependency.

Learn more

+ add another resource

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Powered by Algolia
About Packages

Using packages here is powered by Skypack, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ES6 import usage.

All packages are different, so refer to their docs for how they work.

If you're using React / ReactDOM, make sure to turn on Babel for the JSX processing.

Behavior

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML 

              
                .container
	.title-container
		h1.title.code &lt;details&gt; &amp; &lt;summary&gt;
		
	.card-list
		.card
			h3.card-title.code.code-details &lt;details&gt;
			p.card-description works like an accordian - but without the need for script, supported by most major browsers (except IE & Edge)

		.card
			h3.card-title.code.code-summary &lt;summary&gt;
			p.card-description To customize the title of 
				span.code &lt;details&gt;
				|  tag (of which would fallback to 'details' in most cases)

	.sample
		.sample-title code
		.sample-code
			.code 
				span.code-details &lt;details&gt;
				br
				| &nbsp;&nbsp;
				span.code-summary &lt;summary&gt;
				br
				| &nbsp;&nbsp;&nbsp;&nbsp;What did the cat says when the mouse got away?
				br
				| &nbsp;&nbsp;
				span.code-summary &lt;/summary&gt;
				br
				| &nbsp;&nbsp;You have got to be kitten me!
				br
				span.code-details &lt;/details&gt;

		.sample-title output
		.sample-html
			details.sample-html-details
				summary.sample-html-summary What did the cat says when the mouse got away?
				.speech You have got to be kitten me!
!

CSS 

              
                $purple: #9796F0
$purple-dark: #783F8E
$pink: #FBC7D4
$pink-hot: #E36588
$green-pale: #E4F0D0
$grey: #738290
$rice: #FFFCF7
$white: #FFF
$pad: 20px
$ease-back: cubic-bezier(0.01, 0.29, 0.38, 2.37)

@mixin mobile
	@media (max-width: 500px)
		@content
	
.container
	padding: 0 $pad
	max-width: 800px
	margin: 0 auto

.title
	font-size: 3rem
	display: inline-block
	color: $purple
	background: linear-gradient(to right, $purple-dark, $purple 20%, $pink, $pink-hot)
	-webkit-background-clip: text
	-webkit-text-fill-color: transparent
	
.card
	border-radius: 10px
	background: $white
	padding: $pad
	box-shadow: 4px 4px 12px 1px rgba(0, 0, 0, 0.2)
	line-height: 1.5

	& + &
		margin-left: $pad

	&-list
		display: flex
		flex: 1
	
	&-title
		margin: 0 0 $pad 0
		letter-spacing: 1px
	
	&-description
		margin: 0
	
	&-details
		.card-title
			color: $purple-dark
	
	&-summary
		.card-title
			color: $pink-hot
	
	@include mobile
		flex: 1

.sample
	margin-top: $pad * 2
	border-radius: 10px
	overflow: hidden

	&-title
		line-height: 2
		font-size: 0.75rem
		background: $grey
		color: $white
		padding: 0 $pad
		letter-spacing: 1px 
	
		@extend .code

	&-code
		border-left: 2px dashed $green-pale
		border-right: 2px dashed $green-pale
		padding: $pad
		line-height: 1.5
	
	&-html
		padding: $pad
		background: $green-pale
	
		&-details
			&[open]
				.sample-html-summary:before
					content: '🙀'
					animation: cat 0.2s $ease-back

		&-summary
			list-style-image: none
			cursor: pointer
			padding-left: $pad * 3
			position: relative
	
			&:before
				content: '😼'
				position: absolute
				top: calc(50% - 18px)
				left: 0
				font-size: 2rem
	
			&:focus
				outline: none
	
			&::-webkit-details-marker
				display: none
			
	
.code
	font-family: 'Fira Mono', monospace

	&-details
		color: $purple-dark
	
	&-summary
		color: $pink-hot

.speech
	display: inline-block
	margin: $pad 0 0 7px
	padding: $pad
	background: $white
	border-radius: 0 10px 10px 10px
	position: relative
	animation: speech 0.3s $ease-back
	transform-origin: top left

	&:before
		content: ''
		position: absolute
		border: 8px solid transparent
		top: -16px
		left: 0
		border-bottom-color: $white
	
\:root
	font-size: 16px

html, body
	width: 100%
	height: 100%
	display: flex
	background: $rice
	color: $grey
	font-family: 'Roboto', sans-serif

*
	box-sizing: border-box
	&:before, &:after
		box-sizing: inherit

@keyframes speech
	from
		opacity: 0
		transform: scale(0.98)
	to
		opacity: 1
		transform: none
	
@keyframes cat
	50%
		transform: scale(1.1)
!

JS
!
999px

Console