Pen Settings

CSS Base

Vendor Prefixing

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.

+ add another resource

You're using npm packages, so we've auto-selected Babel for you here, which we require to process imports and make it all work. If you need to use a different JavaScript preprocessor, remove the packages in the npm tab.

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

Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

⚠️ This feature can only be used by logged in users.

Code Indentation


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.

HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

              <div class="FlexContainer">
  <div class="FlexItem">
    <p>When content is sparse,<br>
      I should be centered.</p>

<div class="FlexContainer">
  <div class="FlexItem">
    <p>When there's lots of content&mdash;more content than can fit inside the flex container&mdash;the container should expand vertically to accomodate.</p>
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer non pulvinar mi, quis aliquam ligula. Aenean cursus sapien augue, vel porta arcu aliquet ut. Cras eu massa eu libero porttitor commodo. Morbi non ante luctus, finibus felis sit amet, dignissim augue. Sed consectetur iaculis nisi sed vestibulum. Integer accumsan auctor justo sed eleifend. Suspendisse id diam lectus. Nullam et volutpat dui. Pellentesque a mauris ac ante viverra elementum. Curabitur tincidunt ac ex ut lobortis. In eget ligula ut sapien convallis feugiat. Duis vehicula eget elit at consectetur. Aliquam pharetra maximus consequat. Fusce mattis vel velit non cursus. Integer sed metus libero. Fusce leo est, suscipit id velit eu, egestas viverra nibh. Duis sed orci augue. Vivamus varius consectetur gravida. Sed id faucibus felis. Morbi a diam nisi. Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
 * Flexbug demo 3.2.a (bug)
 * 1. Flexbug #2 workaround.

.FlexContainer {
  align-items: center;
  background: hsla(0,0%,0%,.1);
  display: flex;
  flex-direction: column;
  justify-content: center;
  margin: 1em;
  padding: 2em;
  min-height: 250px;
  width: 400px;

.FlexItem {
  background: hsla(0,0%,0%,.1);
  box-sizing: border-box; /* 1 */
  max-width: 100%; /* 1 */
  padding: 0 1em;

🕑 One or more of the npm packages you are using needs to be built. You're the first person to ever need it! We're building it right now and your preview will start updating again when it's ready.