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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.

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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.

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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.

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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

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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.

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JavaScript

About JavaScript Preprocessors

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

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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.

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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.

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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.

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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.

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HTML 

              
                <div class="wrapper wrapper1"  id="wrapper">
  <p class="click-text">
    What does Marsellus Wallace not look like? <span class="arrow"></span>
  </p>
  <ul>
    <li>Black</li>
    <li>Bald</li>
    <li>A Bitch</li>
  </ul>  
</div>

<div class="wrapper wrapper2"  id="wrapper2">
  <p class="click-text">
    Malkovich malkovich? <span class="arrow"></span>
  </p>
  <ul>
    <li>Malkovich</li>
    <li>Malkovich</li>
    <li>Malkovich</li>
  </ul>  
</div>

<div class="wrapper wrapper3"  id="wrapper3">
  <p class="click-text">
    What is your favourite colour? <span class="arrow"></span>
  </p>
  <ul>
    <li>Blue</li>
    <li>Yellow</li>
    <li>Not Sure</li>
  </ul>  
</div>
!

CSS 

              
                body
  color: white
  font-family: sans-serif
  background-color: #616161
  font-family: 'Source Sans Pro', sans-serif

.wrapper
  margin: 40px auto
  width: 400px
  display: block
  text-align: center
  transition: 0.15s ease
  &.active
    .arrow 
      transform: rotate(45deg) translate(-5px,-5px)
      &:before
        transform: translate(10px,0)
      &:after
        transform: rotate(90deg) translate(10px,0)
    ul
      opacity: 0.3
      height: 108px
      
.wrapper2
  ul
    border: 1px solid rgba(255, 255, 255, 0.5)
  li
    &:first-child
      margin-top: 16px
    &:last-child
      margin-bottom: 3px
  &.active
    ul
      margin-top: 12px
    .arrow
      transform: rotate(45deg) translate(38px,38px)
      opacity: 0.6
      &:before
        transform: translate(5px,0)
      &:after
        transform: rotate(90deg) translate(5px,0)

.wrapper3
  .arrow
    transform: rotate(0)
    left: 0
    &:before, &:after
      background-color: transparent
      width: 3px
      height: 10px
      display: inline-block
      position: absolute
      border-bottom: 12px solid white
      top: 0
      left: 0
      transform: rotate(0)
    &:before
      transform: rotate(-135deg)
    &:after 
      transform: rotate(135deg)
      
  &.active
    .arrow
      transform: rotate(0)
      transform: translate(0, -6px)
      &:before
        transform: rotate(-45deg)
      &:after
        transform: rotate(45deg)
      
  

.arrow
  width: 13px
  height: 13px
  display: inline-block
  position: relative
  bottom: -5px
  left: -10px
  transition: 0.4s ease
  margin-top: 2px
  text-align: left
  transform: rotate(45deg)
  float: right
  &:before, &:after
    position: absolute
    content: ''
    display: inline-block
    width: 12px
    height: 3px
    background-color: #fff
    transition: 0.4s ease
  &:after
    position: absolute
    transform: rotate(90deg)
    top: -5px
    left: 5px
  
.click-text 
  display: block
  text-align: left
  padding: 0 12px 16px
  margin: 0
  cursor: pointer
  color: rgba(255, 255, 255, 0.3)
  border-bottom: 1px solid rgba(255, 255, 255, 0.2)
  transition: 0.15s ease
  &:hover
    color: rgba(255, 255, 255, 0.6)
    border-bottom-color: rgba(255, 255, 255, 0.4)
  
ul
  padding: 0
  margin: 0
  height: 0
  overflow: hidden
  opacity: 0
  transition: 0.4s ease
  border-bottom: 1px solid rgba(255, 255, 255, 0.5)

li
  list-style-type: none
  margin: 0 auto
  padding: 4px 12px
  text-align: left
  cursor: pointer
  &:first-child
    margin-top: 12px
  &:last-child
    margin-bottom: 12px
!

JS 

              
                document.getElementById('wrapper').onclick = function() {

    var className = ' ' + wrapper.className + ' ';

    this.className = ~className.indexOf(' active ') ?
                         className.replace(' active ', ' ') :
                         this.className + ' active';
};

document.getElementById('wrapper2').onclick = function() {

    var className = ' ' + wrapper2.className + ' ';

    this.className = ~className.indexOf(' active ') ?
                         className.replace(' active ', ' ') :
                         this.className + ' active';
}

document.getElementById('wrapper3').onclick = function() {

    var className = ' ' + wrapper3.className + ' ';

    this.className = ~className.indexOf(' active ') ?
                         className.replace(' active ', ' ') :
                         this.className + ' active';
}
!
999px

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