Pen Settings



CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs 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 its URL and the proper URL extension.

+ 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.


Auto Save

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.


                %h1 Rainbow with Sass & Compass

%h2 My Rainbow:


  For a website, I wanted to make a reusable mixin
  that uses CSS background gradients to create a
  colour stripe effect. My version was hard-coded to
  take 8 colour values. It also was pretty verbose.
  Finally, it only allowed stripes to go from left
  to right.

  I knew it could be done much better, so I
  %a(href="") tweeted out a request
  for a Sass expert to show me a better way to write
  my mixin.
  Shortly after I tweeted that, I received an
  %a(href="") amazing contribution
  from @eriiicam. I was amazed at what Sass is
  capable of doing. They look identical, but with his
  improvements, I can give it as many colours as I
  want, and I can have the stripes go in whichever
  direction I want. It's also not verbose like mine was.

%h2 His Rainbow:


  A huge thanks goes to Eric for his help on this.
  I thought it was so cool that I wanted to share it
  here. While I posted the idea for the mixin, I want 
  to stress that Eric did the Sass Function. I hope 
  you find it as helpful as I did.:)


                @import compass

$link: #369

  padding: 24px
  font: 16px/1.5 Helvetica, Arial, sans-serif
  background: #fff
  color: #444

  text-decoration: none
    color: $link
    color: darken($link, 10%)
    color: darken($link, 20%)

  margin: 0
  padding: 1em 0 0
  font-size: 1em
  text-transform: uppercase
  color: #888

  color: #666

// -------------------------------------------

$stripe-width:  100% / 8

$stripe-1: #c00
$stripe-2: #f90
$stripe-3: #ff6
$stripe-4: #693
$stripe-5: #3cc
$stripe-6: #09c
$stripe-7: #33c
$stripe-8: #96c

  +background-image(linear-gradient(left, $stripe-1, $stripe-1 $stripe-width, $stripe-2 $stripe-width, $stripe-2 $stripe-width * 2, $stripe-3 $stripe-width * 2, $stripe-3 $stripe-width * 3, $stripe-4 $stripe-width * 3, $stripe-4 $stripe-width * 4, $stripe-5 $stripe-width * 4, $stripe-5 $stripe-width * 5, $stripe-6 $stripe-width * 5, $stripe-6 $stripe-width * 6, $stripe-7 $stripe-width * 6, $stripe-7 $stripe-width * 7, $stripe-8 $stripe-width * 7, $stripe-8))

  height: 1em
  +box-shadow(0 1px 2px rgba(#000, .25) inset)

// -------------------------------------------

// Using the above colours
$colours: $stripe-1, $stripe-2, $stripe-3, $stripe-4, $stripe-5, $stripe-6, $stripe-7, $stripe-8

@function stripes($position, $colours)
  $colours: if(type-of($colours) != 'list', compact($colours), $colours)
  $gradient: compact()
  $width: 100% / length($colours)

  @for $i from 1 through length($colours)
    $pop: nth($colours,$i)
    $new: $pop ($width * ($i - 1)), $pop ($width * $i)
    $gradient: join($gradient, $new, comma)

  @return linear-gradient($position, $gradient)

  height: 1em
  +background-image(stripes(left, ($colours)))
  +box-shadow(0 1px 2px rgba(#000, .25) inset)