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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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.

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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.

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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.

  // Loads the Flowbox Embed script
  (function(d, id) {
    if (!window.flowbox) { var f = function () { f.q.push(arguments); }; f.q = []; window.flowbox = f; }
    if (d.getElementById(id)) {return;}
    var s = d.createElement('script'), fjs = d.scripts[d.scripts.length - 1]; s.id = id; s.async = true;
    s.src = ' https://connect.getflowbox.com/flowbox.js';
    fjs.parentNode.insertBefore(s, fjs);
  })(document, 'flowbox-js-embed');

<div class="tags">
  <button data-tag="fish" class="active">Fish</button>
  <button data-tag="meat">Meat</button>
  <button data-tag="vegetarian">Vegetarian</button>
  <button data-tag="burger">Burgers</button>

<div id="js-flowbox-flow"></div>
  // Initializes the Flowbox Embed into the #js-flowbox-flow div
  window.flowbox('init', {
    container: '#js-flowbox-flow',
    key: '00iOvX6IRjSQshRMTLAn7A',
    tags: ['fish']
              body {
  background: #333;
  padding-top: 40px;

.tags {
  display: flex;
  justify-content: center;
  margin-bottom: 50px;

button {
  background: #fafafa;
  border: none;
  border-bottom: 5px solid white;
  border-right: 1px solid #ccc;
  color: #333;
  cursor: pointer;
  display: inline-block;
  height: 50px;
  margin: 0;
  margin-bottom: 20px;
  outline: none;
  font-weight: bold;
  font-size: 17px;
  text-transform: uppercase;
  padding-bottom: 3px;
  letter-spacing: 0.5px;

button.active {
  border-bottom: 5px solid #0080ff;
 * Defines a function that takes a tag and updates the Flow
 * (using the same key as the script in our HTML code)
function updateFlow (tag) {
  window.flowbox('update', {
    key: '00iOvX6IRjSQshRMTLAn7A',
    tags: [tag],

// Gets all our buttons
const buttons = document.querySelectorAll('button[data-tag]')

// Function for looping through all buttons and clearing their classes
function clearButtonClasses () {
  for (const button of buttons) {

// Loops through all our buttons and adds click handlers
for (const button of buttons) {
  button.addEventListener('click', () => {
    // When clicking the button, use its data-tag attriibute to update the Flow
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