Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

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.

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JavaScript

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.

+ 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.

Behavior

Auto Save

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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

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Visit your global Editor Settings.

HTML

              
                <div id="spread"></div>
<main>
  <h1>Hello JS!</h1>
  <img class="main-image" src="https://assets.codepen.io/85188/picnic.jpg" alt="picnic" />
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam lacinia rhoncus nulla, a finibus enim ornare eget. Integer ullamcorper dolor at massa accumsan gravida. Maecenas gravida iaculis orci eget lacinia. Maecenas molestie sem sapien, ut cursus felis aliquam sed. Vivamus non sapien mattis, ultricies nisi et, imperdiet dui. Ut lacinia, elit quis elementum laoreet, enim lectus molestie ipsum, eu blandit lectus purus at neque. Suspendisse tincidunt lorem et elit volutpat sodales. Maecenas iaculis fermentum eros a bibendum. In ullamcorper tincidunt tellus id suscipit. Cras a elit sem. Fusce vel diam lacus. Nulla iaculis risus at neque convallis molestie.</p>
</main>
              
            
!

CSS

              
                #spread {
  position: absolute;
  top: 0;
  width: 100%;
  height: 100vh;
  background: #000;
}

/* General styling */
main {
  max-width: 600px;
  text-align: center;
  margin: auto;
}
p {
  text-align: left;
}
 
              
            
!

JS

              
                window.onload = function () {
  document.getElementById("spread").animate(
    {
      height: 0,
      opacity: 0.5
    },
    {
      fill: "forwards",
      duration: 1000,
      easing: "ease-in"
    }
  );
};

              
            
!
999px

Console