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 URL's 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 it's URL and the proper URL extention.

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 

              
                ul.content
	li#content-item-01.content__item
		div.content__item__text
			| item1
	li#content-item-02.content__item
		div.content__item__text
			| item2
	li#content-item-03.content__item
		div.content__item__text
			| item3
!

CSS 

              
                @import 'nib'

cWidth = 30px
sWidth = 200px

createGradient(type, str)
	dev = 20
	spl = 100 / dev
	for i in (0..dev)
		if i % 2 == 1
			if i
				str = str + ',#888 ' + ((i - 1) * spl) + '.01%'
			str = str + ',#888 ' + (i * spl) + '%'
		else
			if i
				str = str + ',#000 ' + ((i - 1) * spl) + '.01%'
			str = str + ',#000 ' + (i * spl) + '%'
	if type == 'linear'
		str = 'linear-gradient(' + str + ')'
	else
		str = 'radial-gradient(' + str + ')'
	background-image unquote(str)

body
	display flex
	flex-flow row nowrap
	align-items center
	justify-content stretch
	min-height 100vh

.content
	width 100%
	min-height 100vh
	background-color #ff0
	display flex
	flex-flow row nowrap
	align-items stretch
	justify-content stretch
	
	&__item
		display inline-block
		background-color #0ff
		width 33%
		flex-grow 1
		flex-shrink 1
		display flex
		flex-flow column nowrap
		justify-content center
		align-items center
		position relative
		overflow hidden
		transition all .2s ease 0s
		z-index 10

		&__text
			size 80px
			background-color #fff
			display flex
			flex-flow column nowrap
			justify-content center
			align-items center
			border-radius 50%
			position relative
			z-index 4
			font-size 14px
			transition all .2s ease 0s

		&:hover
			width 50%
			flex-glow 2

			& ^[1]__text
				size 120px
				font-size 18px

		&::before
		&::after
			content ''
			absolute left 50% top 50%
			size 100vmax
			margin-top -50vmax
			margin-left -50vmax
			animation-duration 20s
			animation-timing-function linear
			animation-delay 0s
			animation-iteration-count infinite
			animation-direction	normal
			
		&::before
			mix-blend-mode overlay
			animation-name cont_anim1
			z-index 1

		&::after
			mix-blend-mode overlay
			animation-name cont_anim2
			z-index 2
		
		color-high = #aaa
		color-low = #888

		&:nth-child(1)
			background-image linear-gradient(
				bottom left,
				#ff8 0%,
				#f88 100%
			)
			
			&::before
				background-image repeating-linear-gradient(
					-45deg,
					color-high 0px, color-high 10px,
					color-low 10px, color-low 20px
				)

			&::after
				background-image repeating-linear-gradient(
					45deg,
					color-high 0px, color-high 10px,
					color-low 10px, color-low 20px
				)

		&:nth-child(2)
			background-image linear-gradient(
				bottom left,
				#f8f 0%,
				#88f 100%
			)
			
			&::before
				background-image repeating-radial-gradient(
					-45deg,
					color-high 0%, color-high 2%,
					color-low 2%, color-low 4%
				)
				animation-name cont_anim3

			&::after
				background-image repeating-linear-gradient(
					45deg,
					color-high 0px, color-high 10px,
					color-low 10px, color-low 20px
				)

		&:nth-child(3)
			background-image linear-gradient(
				bottom left,
				#8ff 0%,
				#8f8 100%
			)
			
			&::before,
			&::after
				background-image radial-gradient(
					color-low 40%,
					transparent 0
				), radial-gradient(
					color-low 40%,
					transparent 0
				)
				background-color color-high
				background-position 0 0, 10px 10px
				background-size 20px 20px

	@keyframes cont_anim1
		to
			transform rotate(0deg)
		from
			transform rotate(360deg)

	@keyframes cont_anim2
		to
			transform rotate(360deg)
		from
			transform rotate(0deg)

	@keyframes cont_anim3
		0%
			size 100vmax
			margin-top -50vmax
			margin-left -50vmax
		50%
			size 200vmax
			margin-top -100vmax
			margin-left -100vmax
		100%
			size 100vmax
			margin-top -50vmax
			margin-left -50vmax
!

JS
!
999px

Console