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.

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Babel is required to process package imports. If you need a different preprocessor remove all packages first.

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.

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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

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                <div id="page">
<input class="toggle-box" id="identifier-1" type="checkbox">
<label for="identifier-1">Click here to read more about HTML!</label>
<div>As you may know, HTML (HyperText Markup Language) - is a language for web page markup. Its main goal is to translate information given in the form of readable content. Mostly, because of HTML, we see the Web as it is, we see its beauty, color and multi-functionality.</div>
<input class="toggle-box" id="identifier-2" type="checkbox">
<label for="identifier-2">Click here to read more about CSS!</label>
<div>Cascading Style Sheets allow you to keep the color, text size, and other parameters in styles. A style is a set of formatting rules, which are applied to some parts of a document to quickly change its appearance.</div>


                .toggle-box {
  display: none;

.toggle-box + label {
  cursor: pointer;
  display: block;
  font-weight: bold;
  line-height: 21px;
  margin-bottom: 5px;

.toggle-box + label + div {
  display: none;
  margin-bottom: 10px;

.toggle-box:checked + label + div {
  display: block;

.toggle-box + label:before {
  background-color: #4F5150;
  -webkit-border-radius: 10px;
  -moz-border-radius: 10px;
  border-radius: 10px;
  color: #FFFFFF;
  content: "+";
  display: block;
  float: left;
  font-weight: bold;
  height: 20px;
  line-height: 20px;
  margin-right: 5px;
  text-align: center;
  width: 20px;

.toggle-box:checked + label:before {
  content: "\2212";