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HTML

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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

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About the <head>

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Insecure Resource

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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).

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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.

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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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Using packages here is powered by Skypack, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ES6 import usage.

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

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HTML 

              
                <body class="theme-transit">
  <section id="content">
    <h1>Subway - Red Line</h1>
    <div class="dropdown">
      <div class="title">Telefonplan</div>
      <ul>
        <li>Liljeholmen</li>
        <li>Midsommarkransen</li>
        <li>Telefonplan</li>
      </ul>
    </div>
  </section>
</body>
!

CSS 

              
                @import "compass/css3";

/* OPTIONS */

$list_opacity: 0.2;
$border_radius: 3px;
$width: 300px;

/* STYLES */
section#content {
  width: $width;
  position: fixed;
  left: 50%;
  top: 50px;
  margin-left: -150px;
  text-align: center;
}
h1 {
  color: white;
  text-shadow: 0px 2px 1px black;
  margin-bottom: 1em;
}
div.dropdown {
  text-align: left;
  font-size: 0.9em;
  color: rgb(240, 240, 240);
  text-shadow: 0px 1px 1px black;
  width: inherit;
  
  &.closed {
    ul {
      margin-top: 0px;
      li {
        margin-top: -40px;
        height: 0px;
      }
    }
    div.title:after {
      margin-top: -14px;
      @include transform(rotate(0deg));
    }
  }
  
  div.title {
    width: 100%;
    height: 40px;
    border: 1px solid rgba(25,25,25,0.3);
    padding: 12px;
    cursor: pointer;
    @include box-sizing("border-box");
    @include background-image(linear-gradient(top, rgba(230, 230, 230, $list_opacity), rgba(160, 160, 160, $list_opacity)));
    @include border-radius($border_radius);
    @include box-shadow(0px 1px 0px 0px rgba(0,0,0,0.3), 0px 2px 6px rgba(0,0,0,0.3));
    
    &:after {
      display: block;
      content: "▾";
      position: absolute;
      right: 20px;
      margin-top: -12px;
      @include transform(rotate(180deg));
    }
  }
  
  ul {
    overflow: hidden;
    @include transition(margin-top 1s);
    @include box-sizing("border-box");
    @include box-shadow(0px 1px 0px 0px rgba(0,0,0,0.3), 0px 2px 6px rgba(0,0,0,0.3));
    @include border-radius(0px 0px $border_radius $border_radius);
    
    li {
      width: 100%;
      height: 40px;
      border: 1px solid rgba(25,25,25,0.3);
      padding: 12px;
      vertical-align: top;
      overflow: hidden;
      cursor: pointer;
      @include transition(margin-top 0.5s, height 0.5s);
      @include box-sizing("border-box");
      @include background-image(linear-gradient(top, rgba(230, 230, 230, $list_opacity), rgba(160, 160, 160, $list_opacity)));
      
      &:first-child {
        border-bottom: none;
        border-top: none;
      }
      &:last-child {
        border-top: none;
        @include border-radius(0px 0px $border_radius $border_radius);
      }
      &:hover {
        text-shadow: 0px 1px 1px black, 0px 0px 4px white;
      }
      &:before {
        content: " ";
        display: inline-block;
        position: relative;
        background: transparent url("http://www.carlcalderon.com/pen/img/line-stop.png");
        margin-top: -12px;
        margin-right: 10px;
        width: 20px;
        height: 40px;
        @include opacity(0.7);
        @include transition(all 0.5s);
      }
    }
  }
}
!

JS 

              
                $(".dropdown .title").click(function () {
  $(this).parent().toggleClass("closed");
});

$(".dropdown li").click(function () {
  $(this).parent().parent().toggleClass("closed").find(".title").text($(this).text());
});
!
999px

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