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. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

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.

If the stylesheet 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 CSS 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

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 

              
                <!-- This example illustrates how to create layout of slides stacked on each  other(especially useful for fade in/out transitions). It's achieved without setting their height and avoiding position: absolute; so they are fully flexible and easy to keep in normal page flow. -->
<input type="radio" name="switch" id="i_1">
<input type="radio" name="switch" id="i_2">
<input type="radio" name="switch" id="i_3" checked>
<input type="radio" name="switch" id="i_4">
<input type="radio" name="switch" id="i_5">
<input type="radio" name="switch" id="i_6">
<div class="wrapper">
  <div class="slide">
    <div class="content content1">
        <p>Nullam quis pretium nisl, suscipit imperdiet metus. Fusce efficitur odio id dolor egestas, quis dignissim orci consequat. Pellentesque libero nunc, volutpat et ligula eu, aliquam iaculis odio. 
          <p>In venenatis aliquet ligula sed accumsan. Maecenas imperdiet a ligula eleifend consectetur.

<p>Nam a urna dapibus, lobortis lectus vitae, blandit dolor. Donec elementum elit vitae egestas feugiat. Praesent eu mauris quis leo molestie eleifend. Donec est nisl, facilisis nec venenatis vitae, efficitur et augue. Donec fringilla dui dui, nec viverra metus viverra et. Etiam nec convallis est, in cursus nisi. Integer vel ullamcorper ante.  <p>Pellentesque et viverra risus. Duis volutpat felis sit amet dictum fermentum. Fusce condimentum porta diam, ut commodo orci accumsan sed. Aenean mi leo, lobortis eu porta a, mattis malesuada nisi. Morbi varius efficitur nisi ac mollis. Fusce et mauris vitae sem varius porttitor. 
      <p>Nullam vel elit massa. Nam sed egestas neque, ut sollicitudin urna. Curabitur vestibulum felis vitae sapien venenatis mattis.

<p>Praesent mattis est faucibus tellus eleifend viverra. Nam non lectus vulputate lacus tristique fermentum. Fusce venenatis mollis imperdiet. Nunc dictum nisi quis mauris varius tincidunt. Suspendisse imperdiet felis lectus. Nunc pharetra tellus ac nulla scelerisque pulvinar. Fusce non blandit dui, sed facilisis neque. Donec gravida nibh dolor, vitae imperdiet lorem varius et. Maecenas pulvinar enim eget velit porta lobortis. Pellentesque sagittis tristique fermentum. <p>Aliquam pretium magna sed consectetur pellentesque. Maecenas id sem eu urna molestie lobortis lacinia nec nulla. Donec tristique tellus lectus, eu faucibus erat tincidunt non. Nunc ut mollis velit.
    </div>   
  </div>
  <div class="slide">
    <div class="content content2">
      <span>♫</span>
    </div>    
  </div>
  <div class="slide">
    <div class="content content3">
      
    </div>
  </div>
  <div class="slide">
    <div class="content content4">
  <p>Nullam vel elit massa. Nam sed egestas neque, ut sollicitudin urna. Curabitur vestibulum felis vitae sapien venenatis mattis.

<p>Praesent mattis est faucibus tellus eleifend viverra. Nam non lectus vulputate lacus tristique fermentum. Fusce venenatis mollis imperdiet. Nunc dictum nisi quis mauris varius tincidunt. Suspendisse imperdiet felis lectus. Nunc pharetra tellus ac nulla scelerisque pulvinar. Fusce non blandit dui, sed facilisis neque. Donec gravida nibh dolor, vitae imperdiet lorem varius et. Maecenas pulvinar enim eget velit porta lobortis. Pellentesque sagittis tristique fermentum. <p>Aliquam pretium magna sed consectetur pellentesque. Maecenas id sem eu urna molestie lobortis lacinia nec nulla. Donec tristique tellus lectus, eu faucibus erat tincidunt non. Nunc ut mollis velit.     
    </div>    
  </div>
  <div class="slide">
    <div class="content content5">
      <span>♪</span>
    </div>    
  </div>
  <div class="slide">
    <div class="content content6">
      <span>♬</span>
    </div>   
  </div>  
</div>
<div class="controls">
  <label for="i_1">⬤</label>
  <label for="i_2">⬤</label>
  <label for="i_3">⬤</label>
  <label for="i_4">⬤</label>
  <label for="i_5">⬤</label>
  <label for="i_6">⬤</label>
</div>
<a target="_blank" href="https://twitter.com/kamildyrek"><svg style="width:2em;height:2em;position:fixed;top:1em;left:1em;opacity:.8;" viewBox="0 0 24 24"><path fill="#fff" d="M17.71,9.33C18.19,8.93 18.75,8.45 19,7.92C18.59,8.13 18.1,8.26 17.56,8.33C18.06,7.97 18.47,7.5 18.68,6.86C18.16,7.14 17.63,7.38 16.97,7.5C15.42,5.63 11.71,7.15 12.37,9.95C9.76,9.79 8.17,8.61 6.85,7.16C6.1,8.38 6.75,10.23 7.64,10.74C7.18,10.71 6.83,10.57 6.5,10.41C6.54,11.95 7.39,12.69 8.58,13.09C8.22,13.16 7.82,13.18 7.44,13.12C7.81,14.19 8.58,14.86 9.9,15C9,15.76 7.34,16.29 6,16.08C7.15,16.81 8.46,17.39 10.28,17.31C14.69,17.11 17.64,13.95 17.71,9.33M12,2A10,10 0 0,1 22,12A10,10 0 0,1 12,22A10,10 0 0,1 2,12A10,10 0 0,1 12,2Z" /></svg></a>
!

CSS 

              
                @import url("https://fonts.googleapis.com/css?family=Lato:400,400i,700");

/* Some resets, not essencial for this example to work */

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
}

input {
  opacity: 0;
  width: 0;
  height: 0;
  position: absolute;
}

/* Base styles for this example */

.wrapper {
  width: 50vw; /* unfortunately width has to be set to some hard value */
  display: flex;
}

.slide {
  width: 0;
}

.content {
  width: 50vw;
  height: 100%; /* this is optional if you want every slide to have same height as the highest one */
}

/* Additional styling */

html, body {
  background-color: #BDBDBD;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center; 
  font-family: Lato;
}

.wrapper {
  margin: 0 auto;
  background-color: white;
  box-shadow: 3px 3px 20px #9E9E9E;
}

span {
  background-color: white;
  text-align: center;
  line-height: 4rem;
  width: 4rem;
  border-radius: 8rem;
  color: #616161;
  font-size: 2rem;
}

.content {
  padding: 30px;
  opacity: 0;
  pointer-events: none;
  transition: opacity .6s;
  max-height: 90vh;
  overflow-y: auto;
}

.content2,
.content5,
.content6
{
  display: flex;
  justify-content: center;
  align-items: center;  
  background-color: #E0E0E0;
}

.content3 {
  background-image: url(https://images.unsplash.com/photo-1507473885765-e6ed057f782c?ixlib=rb-1.2.1&q=80&fm=jpg&crop=entropy&cs=tinysrgb&w=800&fit=max&ixid=eyJhcHBfaWQiOjE0NTg5fQ);
  background-size: cover;
  background-position: center;
}
#i_1:checked ~ .wrapper .content1,
#i_2:checked ~ .wrapper .content2,
#i_3:checked ~ .wrapper .content3,
#i_4:checked ~ .wrapper .content4,
#i_5:checked ~ .wrapper .content5,
#i_6:checked ~ .wrapper .content6 {
  opacity: 1;
  pointer-events: auto;
}

label {
  color: #E0E0E0;
  transition-duration: .6s;
  cursor: pointer;
}

#i_1:checked ~ .controls label[for="i_1"],
#i_2:checked ~ .controls label[for="i_2"],
#i_3:checked ~ .controls label[for="i_3"],
#i_4:checked ~ .controls label[for="i_4"],
#i_5:checked ~ .controls label[for="i_5"],
#i_6:checked ~ .controls label[for="i_6"] {
  color: #424242;
}
!

JS
!
999px

Console