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.

              <main class="wrap">
  <div class="mainContent">
    <p>Calc is very handy when you have a fixed width sidebar and a fluid content div. You can add a media query at some point to remove the floats and make both columns a 100% width.</p>
    <p>Browser support is pretty good. The unsupported browsers are Android < 4.4, IE < 9 and Safari/iOS < 6. However, you can always specify a fallback width for these browsers.</p>
    <p>For vendor prefixes, just webkit will do. The moz one is for Firefox 15 and below, so you shouldn't have to worry about that.</p>
  </div> <!-- /mainContent -->
  <div class="sidebar">
  </div>  <!-- /sidebar -->

              * {
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
  box-sizing: border-box;

.wrap {
  overflow: hidden;

.sidebar, .sidebar a {
  color: #fff;
.sidebar, .mainContent {
  padding: 10px;

.sidebar {
  width: 20em;
  background-color: #000;
  float: right;

.mainContent {
  float: left;
    width: 65%; /* fallback for browsers not supporting calc */
    -webit-width: calc(100% - 20em);
  width: calc(100% - 20em);

Loading ..................