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. You can use the CSS from another Pen by using it's URL and the proper URL extention.

+ add another resource


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


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.


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.


                <!DOCTYPE html>
<html lang="en">
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>The Flex Grow Property</title>
    <link rel="stylesheet" href="style.css">
    <div class="container">
        <div class="item item1">1</div>
        <div class="item item2">Lorem ipsum dolor sit, amet consectetur adipisicing elit. Sed id cum eveniet fuga voluptatem? Modi assumenda sapiente dolores iusto quas odit facilis rem quibusdam aliquam illum numquam, dolorem nihil incidunt quam similique dolorum nam, nesciunt placeat maiores cupiditate hic cumque fugiat itaque! Repellat asperiores in earum ab, iste maxime similique accusantium et ex! Neque rem aperiam perspiciatis saepe, sed magni debitis repellendus libero enim obcaecati accusantium id recusandae quaerat quasi. Hic doloribus possimus animi placeat magnam quasi molestias obcaecati temporibus!</div>
        <div class="item item3">3</div>


                /* GLOBAL STYLES */

* {
    box-sizing: border-box;

body {
    background-color: #AAA;
    margin: 0px 50px;

.item {
    padding: 2rem;
    border: 5px solid #87b5ff;
    border-radius: 3px;
    font-size: 2em;
    font-family: sans-serif;
    font-weight: bold;
    background-color: #1c57b5;

.container {
    display: flex;
    background-color: #f5ca3c;
    flex-direction: column;
    height: 90vh;

.item1 {
    flex-grow: 1;
.item2 {
    flex-grow: 2;

.item3 {
    flex-grow: 1;