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 esm.sh, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ESM 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

Auto Save

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 

              
                <div class="count"></div>

<script id="count-template" type="text/template">
 <span class="current top <%= currentSize %>"><%= time %></span>
 <span class="next top <%= nextSize %>"><%= nextTime %></span>
 <span class="current bottom <%= currentSize %>"><%= time %></span>
 <span class="next bottom <%= nextSize %>"><%= nextTime %></span>
</script>
!

CSS 

              
                @import compass

// animation vars
$duration: 0.35s
$bounce: cubic-bezier(0.375, 1.495, 0.610, 0.780)

// dimensions
$height: 300px
$width: 200px

.count
	box-shadow: 0 10px 5px -5px rgba(#000, 0.2)
	height: $height
	left: 50%
	line-height: $height
	margin: -($height / 2) 0 0 -($width / 2)
	+perspective(500px)
	position: absolute
	text-align: center
	top: 50%
	+translateZ(0)
	width: $width

	// the basic "card"
	//    there are four of these: top current, top next, bottom current, and bottom next
	span
		background: #202020
		color: #f8f8f8
		display: block
		font-size: 250px
		left: 0
		position: absolute
		top: 0
		text-shadow: 0 1px 0 (#000 + 40), 0 2px 0 (#000 + 30), 0 3px 0 (#000 + 20), 0 4px 0 (#000 + 10), 0 5px 0 #000, 0 0 10px rgba(#000, 0.8)
		+transform-origin(0, 150px, 0)
		width: 100%

		// the dividing line in the center
		&:before
			border-bottom: 2px solid #000
			content: ''
			left: 0
			position: absolute
			width: 100%

		// a shadow fill that adds some convexity on the card surfaces
		&:after
			box-shadow: inset 0 0 60px rgba(#000, 0.35)
			content: ''
			height: 100%
			left: 0
			position: absolute
			top: 0
			width: 100%

	// two-digit numbers get the 'small' class
	.small
		font-size: 175px

	.top
		// top card sit above the bottom ones, so if we give them the same
		//   border radius they'll create some crunchiness.
		//   instead, go one pixel smaller
		border-top-left-radius: 11px
		border-top-right-radius: 11px

		// creating a light shine on the top of the card
		box-shadow: inset 0 2px rgba(#000, 0.9), inset 0 3px 0 rgba(#fff, 0.4)

		// top cards are only 50% height, and overflow-hidden
		//   so they only show the top of their number
		height: 50%
		overflow: hidden

		&:before
			bottom: 0

		&:after
			// top card needs to get darker as it curves downward
			+background(linear-gradient(rgba(#000, 0), rgba(#000, 0.15)))
			border-top-left-radius: 11px
			border-top-right-radius: 11px

	.bottom
		// bottom cards are 100% height, but their top half is hidden by "top" cards
		//   this was the best way I could think of to show the bottom cards in half, but
		//   there's probably another way using display: table-cell and vertical-align.
		//   ew.
		border-radius: 10px
		height: 100%

		&:before
			top: 50%

		&:after
			border-radius: 10px
			+background(linear-gradient(rgba(#fff, 0.1), rgba(#fff, 0.1) 50%, rgba(#fff, 0)))

	// styles that only apply when counting "down"
	&.down
		.top
			// use a higher number than the bottoms to prevent crunchy border radiuses
			border-top-left-radius: 11px
			border-top-right-radius: 11px
			height: 50%

			&.current
				// required to prevent safari bug: https://bugs.webkit.org/show_bug.cgi?id=61824
				+transform-style(flat)
				z-index: 3

			&.next
				// when counting down, the next top card is rotated towards the user (and invisible)
				+transform(rotate3d(1, 0, 0, -90deg))
				z-index: 4

		.bottom
			border-radius: 10px

			&.current
				z-index: 2

			&.next
				z-index: 1

		&.changing
			.bottom.current
				box-shadow: 0 75px 5px -20px rgba(#000, 0.3)
				+transform(rotate3d(1, 0, 0, 90deg))

				// the current bottom card rotates up to hide itself, and reveal the next one
				+transition(transform $duration ease-in, box-shadow $duration ease-in)

		&.changing,
		&.changed
			.top.next
				// and the next top card rotates into view (after $duration)
				+transition(transform $duration ease-out $duration)
				+transform(none)

	&.up
		.top
			height: 50%

			&.current
				z-index: 4

			&.next
				z-index: 3

		.bottom
			&.current
				z-index: 1

			&.next
				box-shadow: 0 75px 5px -20px rgba(#000, 0.3)

				// when counting "up", the next bottom card begins pointed at the user...
				+transform(rotate3d(1, 0, 0, 90deg))
				z-index: 2

		&.changing
			.top.current
				// and the current top card does the rotating
				+transform(rotate3d(1, 0, 0, -90deg))

				// when the card is "dropping" it should be faster
				+transition(transform $duration * 0.75 ease-in, box-shadow $duration * 0.75 ease-in)

		&.changing,
		&.changed
			.bottom.next
				box-shadow: 0 0 0 0 rgba(#000, 0)

				// add a little bounce at the moment the card finishes falling
				+transition(box-shadow $duration / 2 $bounce $duration, transform $duration $bounce $duration)
				+transform(rotate3d(1, 0, 0, 0))

	&.changed
		.top.current,
		.bottom.current
			display: none

// presentation styles
@import url(https://fonts.googleapis.com/css?family=Oswald)

html,
body
	height: 100%
	width: 100%

body
	background: #202020 url(https://cl.ly/image/040I101f1i0I/planes.jpg) 50% 50%
	background-origin: 50% 50%
	+background-size(cover)
	font-family: 'Oswald'
!

JS 

              
                // underscore loaded

Countdown = function() {
	_(this).bindAll('update', 'executeAnimation', 'finishAnimation');
	this.setVars.apply(this, arguments);
	this.update();
};

Countdown.prototype = {
	duration: 1000,

	setVars: function(time, el, template) {
		this.max = time;
		this.time = time;
		this.el = el;
		this.template = _(template.innerHTML).template();
		this.delta = -1;
	},

	update: function() {
		this.checkTime();
		this.setSizes();

		this.setupAnimation();
		_(this.executeAnimation).delay(20);
		_(this.finishAnimation).delay(this.duration * 0.9);

		_(this.update).delay(this.duration);
	},

	checkTime: function() {
		this.time += this.delta;

		if (this.time === 0) this.delta = 1;
		if (this.time === this.max) this.delta = -1;

		this.delta === 1 ? this.toggleDirection('up', 'down') : this.toggleDirection('down', 'up');

		this.nextTime = this.time + this.delta;
	},

	toggleDirection: function(add, remove) {
		this.el.classList.add(add);
		this.el.classList.remove(remove);
	},

	setSizes: function() {
		this.currentSize = this.getSize(this.time);
		this.nextSize = this.getSize(this.nextTime);
	},

	getSize: function(time) {
		return time > 9 ? 'small' : '';
	},

	setupAnimation: function() {
		this.el.innerHTML = this.template(this);
		this.el.classList.remove('changed');
	},

	executeAnimation: function() {
		this.el.classList.add('changing');
	},

	finishAnimation: function() {
		this.el.classList.add('changed');
		this.el.classList.remove('changing');
	}
};

new Countdown(
	12,
	document.querySelector('.count'),
	document.querySelector('#count-template')
);
!
999px

Console