Pen Settings

HTML

CSS

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

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

Save Automatically?

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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

              
                <!-- remember - codepen abstracts away some of the standard HTML page structure! -->

<!-- <html> (already included) -->
  <!-- <body> (already included) -->
    <h1>Page content</h1>
    
    <p>The body (or any block-level element for that matter) will stretch and change height to accomodate whatever content you put inside it.</p>
  <!-- </body> (already included) -->
<!-- </html> (already included) -->

    <h2>Heading</h2>

    <p>Paragraph.</p>

    <h2>Heading</h2>

    <p>Paragraph.</p>

    <h2>Heading</h2>

    <p>Paragraph.</p>

    <h2>Heading</h2>

    <p>Paragraph.</p>

    <h2>Heading</h2>

    <p>Paragraph.</p>

    <h2>Heading</h2>

    <p>Paragraph.</p>

    <h2>Heading</h2>

    <p>Paragraph.</p>
              
            
!

CSS

              
                
html {
  background-color: wheat;
}

body {
  background-color: lightgray;
  padding: 10px;
  
  /* this will create a 'constraint' */
  width: 80%;
  max-width: 500px;
  /* go ahead and try and be 100% width like normal... 
    but don't ever get bigger than this. */
  
  /* this will confuse the body and center it */
  margin-right: auto;
  margin-left: auto;
}
              
            
!

JS

              
                
              
            
!
999px

Console