cssAudio - Activefile-genericCSS - ActiveGeneric - ActiveHTML - ActiveImage - ActiveJS - ActiveSVG - ActiveText - Activefile-genericVideo - ActiveLovehtmlicon-new-collectionicon-personicon-teamlog-outoctocatpop-outspinnerstartv

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.

Quick-add: + add another resource

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.

Quick-add: + add another resource

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.

  <li>Details &amp; Summary behave a lot like the <a href="https://codepen.io/collection/EdGoh/">accordion design pattern</a>, only just the basics. Could you layer on functionality, like a group of details elements in which only one can be open at once?</li>
  <li>Can you progressively enhance Details &amp; Summary to add custom styling and animation?</li>
  <li>These elements <a href="https://caniuse.com/#feat=details">don't work in Edge</a>. You could have a look at the polyfills out there and perhaps build your own if you'd like to have a go at it.</li>
              @import url("https://fonts.googleapis.com/css?family=Lato:400,400i,700");
ol {
  max-width: 350px;
  counter-reset: my-awesome-counter;
  list-style: none;
  padding-left: 40px;
ol li {
  margin: 0 0 0.5rem 0;
  counter-increment: my-awesome-counter;
  position: relative;
ol li::before {
  content: counter(my-awesome-counter);
  color: #fcd000;
  font-size: 1.5rem;
  font-weight: bold;
  position: absolute;
  --size: 32px;
  left: calc(-1 * var(--size) - 10px);
  line-height: var(--size);
  width: var(--size);
  height: var(--size);
  top: 0;
  transform: rotate(-10deg);
  background: black;
  border-radius: 50%;
  text-align: center;
  box-shadow: 1px 1px 0 #999;

body {
  background: #191919;
  color: #eee;
  font-family: Lato, sans-serif;
  line-height: 1.4;
  font-size: 90%;
  margin: 2rem;
Loading ..................