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 CSS

These stylesheets will be added in this order and before the code you write in the CSS editor. You can also add another Pen here, and it will pull the CSS from it. Try typing "font" or "ribbon" below.

Quick-add: + add another resource

Add External JavaScript

These scripts will run in this order and before the code in the JavaScript editor. You can also link to another Pen here, and it will run the JavaScript from it. Also try typing the name of any popular library.

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 ..................