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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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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

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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-.

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

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Packages

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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.

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HTML 

              
                <div class="container">
  <div class="col col-1">
    <h2>Lorem Ipsum</h2>
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Tellus mauris a diam maecenas sed enim ut sem. Morbi enim nunc faucibus a. Nibh sit amet commodo nulla facilisi nullam. Volutpat consequat mauris nunc congue nisi.</p>
  </div>
  <div class="col col-2">
    <h2>sollicitudin tempor id</h2>
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Porta lorem mollis aliquam ut. Malesuada fames ac turpis egestas. Nibh tortor id aliquet lectus proin nibh nisl condimentum. Lectus vestibulum mattis ullamcorper velit sed ullamcorper. Sed elementum tempus egestas sed sed. Ornare quam viverra orci sagittis eu volutpat odio facilisis mauris. Nibh ipsum consequat nisl vel pretium. Magnis dis parturient montes nascetur. Massa vitae tortor condimentum lacinia quis. Ultricies mi eget mauris pharetra et ultrices neque ornare aenean. Etiam dignissim diam quis enim lobortis scelerisque fermentum.</p>
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Vel fringilla est ullamcorper eget nulla facilisi etiam dignissim diam. Sed viverra ipsum nunc aliquet bibendum enim facilisis gravida. Pellentesque massa placerat duis ultricies lacus sed turpis tincidunt id. Potenti nullam ac tortor vitae purus faucibus ornare. Elit sed vulputate mi sit amet mauris.</p>
  </div>
  <div class="col col-3">
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. In egestas erat imperdiet sed euismod nisi. Eget nullam non nisi est sit amet facilisis. Mus mauris vitae ultricies leo.</p>
  </div>
</div>
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CSS 

              
                h2 {
  color: red;
  font-size: 2rem;
}

.container {
  margin: 0 auto;
}

.col {
  margin: 0.5em;
  padding: 0 1em;
}

.col-1,
.col-3 {
  width: 20%;
}

.col-1 {
  box-shadow: 2px 2px 5px red;
}

.col-2 {
  background-color: skyblue;
  width: 45%;
}

.col-3 {
  border: 2px solid black;
}

@media (min-width: 640px) and (orientation: landscape) {
  h2 {
    color: blue;
    font-size: 2.5rem;
  }

  .container {
    display: flex;
    justify-content: space-between;
  }

  .col-2 {
    background: yellow;
  }
}
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JS
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999px

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