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.


                <div class="calculator">

  <!-- the input -->
  <input type="number">

  <!-- the buttons -->
  <div class="calculator-buttons">
    <button class="calc-button is-clear">C</button>
    <button class="calc-button">&divide;</button>

    <button class="calc-button">7</button>
    <button class="calc-button">8</button>
    <button class="calc-button">9</button>
    <button class="calc-button">&times;</button>

    <button class="calc-button">4</button>
    <button class="calc-button">5</button>
    <button class="calc-button">6</button>
    <button class="calc-button">&minus;</button>

    <button class="calc-button">1</button>
    <button class="calc-button">2</button>
    <button class="calc-button">3</button>
    <button class="calc-button">&plus;</button>

    <button class="calc-button is-zero">0</button>
    <button class="calc-button is-equals">&equals;</button>


                @import url('');

/* quick reset so all our padding is the right size */
* {
  box-sizing: border-box;

.calculator input,
.calc-button   {
  font-family: 'Space Mono';

/* add some spacing */
body          {
  background: #F6F6F6;
  padding-bottom: 30px;
  padding-top: 30px;  

/* limit the width and center */
.calculator   {
  max-width: 400px;
  margin: 0 auto;
  border: 2px solid #111;
  border-radius: 5px;

.calculator input   {
  /* reset basic form styles */
  background: none;
  border: none;
  box-shadow: none;
  outline: none;

  padding: 20px 10px;
  width: 100%;
  border-bottom: 2px solid #111;
  color: #333;
  text-align: right;
  font-size: 40px;
  border-radius: 0;

.calc-button  {
  background: rgba(0, 0, 0, 0.5); /* light background with opacity 50% */
  border: 1px solid #111; /* black border */
  padding: 20px;
  color: #EEE; /* white text */
  border-radius: 5px; /* rounded corners */
  font-size: 22px; /* larger fonts */
  cursor: pointer; /* make it look clickable */

.calculator-buttons {
  /* small spacing within our container */
  padding: 20px;

  /* the grid stuff! */
  display: grid;

  /* create 4 columns */
  grid-template-columns: 1fr 1fr 1fr 1fr;

  /* add the grid gap */
  grid-gap: 15px;

/* span across 3 columns */
.is-clear   {
  grid-column: span 3;

/* go blue */
.is-clear   {
  background: #3572DB;

.is-equals {
  background: #28D060;