Pen Settings

HTML

About HTML Preprocessors

HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

Learn more · Versions

Adding Classes

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. So you don't have access to higher-up elements like the <html> tag. If you want to add classes there that can affect the whole document, this is the place to do it.

About the <head>

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. If you need things in the <head> of the document, put that code here.

!
Insecure Resource

The resource you are linking to is using the 'http' protocol, which may not work when the browser is using https.

CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

Learn more · Versions

CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

We offer two popular choices: Autoprefixer (which processes your CSS server-side) and -prefix-free (which applies prefixes via a script, client-side).

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.

Powered by Algolia
About External Resources

You can apply CSS to your Pen from any stylesheet on the web. Just put a URL to it here and we'll apply it, in the order you have them, before the CSS in the Pen itself.

You can also link to another Pen here (use the .css URL Extension) and we'll pull the CSS from that Pen and include it. If it's using a matching preprocessor, use the appropriate URL Extension and we'll combine the code before preprocessing, so you can use the linked Pen as a true dependency.

Learn more

+ add another resource

JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

Learn more · Versions

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.

Powered by Algolia
About External Resources

You can apply a script from anywhere on the web to your Pen. Just put a URL to it here and we'll add it, in the order you have them, before the JavaScript in the Pen itself.

If the script you link to has the file extension of a preprocessor, we'll attempt to process it before applying.

You can also link to another Pen here, and we'll pull the JavaScript from that Pen and include it. If it's using a matching preprocessor, we'll combine the code before preprocessing, so you can use the linked Pen as a true dependency.

Learn more

+ add another resource

Packages

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.

Powered by Algolia
About Packages

Using packages here is powered by esm.sh, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ESM usage.

All packages are different, so refer to their docs for how they work.

If you're using React / ReactDOM, make sure to turn on Babel for the JSX processing.

Behavior

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.

HTML 

              
                - var sections = ['home', 'about', 'blog', 'contact']

nav#nav
  button.nav-icon#nav-icon: span
  
  ul
    each item in sections
      li: a(href='#' + item)=item
    
each section in sections
  section(id=section)
    h2=section
    p Click on the hamburger menu icon to see the vertical popout menu. Scroll down to see how it adapts to the background color. The menu icon is created using pure CSS, and the color of the menu adapts to the background color of the page by setting mix-blend-mode to "difference". The toggle animation only needs a tiny bit of JavaScript. This demo was tested in the latest versions of Chrome, Firefox and Safari. It also works on mobile.
    
    p Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis nunc tellus, tempor vitae elit ac, ornare aliquet elit. Vivamus ac tincidunt est, vehicula semper neque. Aliquam eu velit mi. Mauris vel lorem sollicitudin, sollicitudin sem vel, pulvinar risus. Pellentesque ac pulvinar erat, quis aliquet lectus. Integer diam odio, auctor non ullamcorper scelerisque, imperdiet non est. Sed vulputate porttitor lorem, sit amet feugiat tortor pretium tristique. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed ultrices, lectus at ultricies tempus, massa lorem tincidunt urna, at porta nulla massa ac est. Aliquam commodo auctor tempus. In molestie nisl eget diam scelerisque, vel porta metus euismod. Praesent venenatis augue dignissim, vestibulum ex eget, vestibulum sem. In varius est leo. Nam id lobortis erat. Etiam et metus sit amet justo consectetur lacinia faucibus in elit. Aenean elit lorem, pellentesque sed pellentesque at, cursus eget felis.
!

CSS 

              
                @import url(https://fonts.googleapis.com/css?family=EB+Garamond|Work+Sans:700)

$color-light: #fff
$color-dark: #111
$font-primary: 'Adobe Garamond Pro', 'EB Garamond', Garamond, Georgia, 'Times New Roman', serif
$font-secondary: 'Work Sans', 'Arial Black', Gadget, sans-serif

*
  box-sizing: border-box
  padding: 0
  margin: 0
  border: 0
  outline: 0
  -webkit-font-smoothing: antialiased

html
  font-size: 10px // rem reset

body
  background: $color-dark
  color: $color-light
  font: #{2.6rem}/1.55 $font-primary

section
  padding: 12.5%
  width: 100%

  &:nth-of-type(even)
    background: $color-light
    color: $color-dark

p
  margin-bottom: 2.5em
  
a
  color: inherit
  text-decoration: none
    
h2
  font: bold 2.8rem $font-secondary
  text-transform: uppercase
  letter-spacing: 5px
  margin-bottom: 2em
  
nav
  mix-blend-mode: difference
  z-index: 100

  ul
    position: fixed
    top: 60px
    right: 5px
    height: 100vh
    visibility: hidden
    pointer-events: none
    list-style: none
    width: 35px

    li
      font: bold 1.5rem $font-secondary
      text-transform: uppercase
      letter-spacing: 2px
      padding: 0.75em 0
      writing-mode: vertical-lr

  &.active ul
    visibility: visible
    pointer-events: initial
    transition-delay: 0.2s


// Inspired by: https://github.com/callmenick/Animating-Hamburger-Icons

.nav-icon
  appearance: none
  background: transparent
  cursor: pointer
  display: inline-block
  height: 35px
  position: fixed
  top: 15px
  right: 15px
  transition: background 0.3s
  width: 35px

  span
    position: absolute
    top: 15px
    left: 5px
    background: $color-light
    display: block
    height: 3px
    right: 5px
    transition: transform 0.3s

    &:before,
    &:after
      width: 100%
      height: 3px
      background: $color-light
      content: ''
      display: block
      left: 0
      position: absolute

    &:before
      top: -8px

    &:after
      bottom: -8px

  .active & span
    transform: rotate(90deg)
!

JS 

              
                var nav = document.getElementById('nav');
var navlinks = nav.getElementsByTagName('a');

function toggleNav() {
    (nav.classList.contains('active')) ? nav.classList.remove('active') : nav.classList.add('active');
  }

document.getElementById('nav-icon').addEventListener('click', function(e) {
    e.preventDefault();
    toggleNav();
});

for(var i = 0; i < navlinks.length; i++) {
    navlinks[i].addEventListener('click', function() {
      toggleNav();
  });
}
!
999px

Console