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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

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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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 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 

              
                <!-- html example -->
<article>
  <h1>Gameboy Color – Green</h1>
  <img src="gameboycolor.jpg" alt='Gameboy Color – Green' />
  <div>
    <h2>$35.00</h2>
    <a href="/buy-product/">Buy now</a>
  </div>
</article>

<!-- short microdata example -->
<article itemscope itemtype="https://schema.org/Product">
  <h1 itemprop="name">Gameboy Color – Green</h1>
  <img itemprop="image" src="gameboycolor.jpg" alt='Gameboy Color – Green' />
  
  <div itemprop="offers" itemscope itemtype="https://schema.org/Offer">
    <h2>
    	<span itemprop="priceCurrency" content="USD">$</span>
    	<span itemprop="price" content="35.00">35.00</span>
    </h2>
    <a href="/buy-product/" itemprop="url" content="/buy-product/">Buy now</a>
  </div>
</article>

<!-- short JSON-LD example -->
<script type="application/ld+json">
  {
    "@context": "https://schema.org",
    "@type": "Product",
    "name": "Gameboy Color - Green",
    "image": "gameboycolor.jpg",
    "offers": {
      "@type": "Offer",
      "price": "35.00",
      "priceCurrency": "USD",
      "url": "/buy-product/"
    }
  }
</script>

<!-- short RDFa example -->
<article vocab="https://schema.org/" typeof="Product">
  <h1 property="name">Gameboy Color - Green</h1>
  <img property="image" src="gameboycolor.jpg" alt='Gameboy Color - Green' />
  
  <div property="offers" typeof="Offer">
    <h2>
      <span property="priceCurrency" content="USD">$</span>
      <span property="price" content="35.00">35.00</span>
    </h2>
    <a property="url" content="/buy-product/" href="/buy-product/">Buy now</a>
  </div>
</article>

<!-- extended microdata example -->
<article itemscope itemtype="https://schema.org/Product">
  <h1 itemprop="name">Gameboy Color – Green</h1>
  <img itemprop="image" src="gameboycolor.jpg" alt='Gameboy Color – Green' />
  
  <div itemprop="offers" itemscope itemtype="https://schema.org/Offer">
    <h2>
    	<span itemprop="priceCurrency" content="USD">$</span>
    	<span itemprop="price" content="35.00">35.00</span>
    </h2>
 
    <meta itemprop="priceValidUntil" content="2021-12-31"/>
	  <link itemprop="availability" href="https://schema.org/InStock" />
    <p>In stock</p>
        
    <a itemprop="url" content="/buy-product/" href="/buy-product/">Buy now</a>
  </div>
  
  <section>
    <h3>Product description</h3>
    <p itemprop="description">Lorem, ipsum dolor sit amet consectetur adipisicing elit. Molestiae, numquam ea illum earum alias tempora quod cupiditate labore dicta nisi, laborum nihil dolorum? Modi nam asperiores obcaecati. Nesciunt, ullam deserunt.</p>
  </section>
  
  <section>
  	<h3>Product details</h3>
    <ul>
      <li>Product ID: <span itemprop="sku">1234567890</span></li>
  	  <li>GTIN: <span itemprop="gtin8">1234567890</span></li>
      <li>Brand: <span itemprop="brand">Nintendo</span></li>
    </ul>
  </section>
  
  
  <section>
    <h3>Product reviews</h3>
    <p itemprop="aggregateRating" itemscope itemtype="https://schema.org/AggregateRating">
      Overall rating: <span itemprop="ratingValue">3.5</span>/5 stars (based on <span itemprop="reviewCount">2</span> customer reviews)
    </p>
    <ol>
      <li itemprop="review" itemscope itemtype="https://schema.org/Review">
        <h5 itemprop="name">Not a happy camper</h5>
        <meta itemprop="datePublished" content="2020-04-01">
        <small>by <span itemprop="author">Ellie</span> on April 1, 2011</small>
        <p itemprop="reviewRating" itemscope itemtype="https://schema.org/Rating">
          <meta itemprop="worstRating" content="1">
          <span itemprop="ratingValue">3.5</span>/<span itemprop="bestRating">5</span>stars
        </p>
        <p itemprop="reviewBody">Kind of disappointed by the quality of the product, but it works pretty well.</p>
      </li>
      
      <li itemprop="review" itemscope itemtype="https://schema.org/Review">
        <h5 itemprop="name">Perfect!</h5>
        <meta itemprop="datePublished" content="2020-07-11">
        <small>by <span itemprop="author">Wario</span> on June 11, 2011</small>
        <p itemprop="reviewRating" itemscope itemtype="https://schema.org/Rating">
          <meta itemprop="worstRating" content="1">
          <span itemprop="ratingValue">5</span>/<span itemprop="bestRating">5</span>stars
        </p>
        <p itemprop="reviewBody">Exactly what I was looking for!</p>
      </li>
    </ol>
  </section>  
</article>

<!-- extended JSON-LD example -->
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Gameboy Color – Green",
  "image": "gameboycolor.jpg",
  "description": "Lorem, ipsum dolor sit amet consectetur adipisicing elit. Molestiae, numquam ea illum earum alias tempora quod cupiditate labore dicta nisi, laborum nihil dolorum? Modi nam asperiores obcaecati. Nesciunt, ullam deserunt.",
  "sku": "1234567890",
  "gtin8": "1234567890",
  "brand": "Nintendo",
  "offers": {
    "@type": "Offer",
    "price": "35.00",
    "availability": "https://schema.org/InStock",
    "priceValidUntil": "2021-12-31",
    "priceCurrency": "USD",
    "url": "/buy-product/"
  },
  "aggregateRating": {
    "@type": "AggregateRating",
    "ratingValue": "3.5",
    "reviewCount": "2"
  },
  "review": [
    {
      "@type": "Review",
      "author": "Ellie",
      "datePublished": "2020-04-01",
      "reviewBody": "Kind of disappointed by the quality of the product, but it works pretty well.",
      "name": "Not a happy camper",
      "reviewRating": {
        "@type": "Rating",
        "bestRating": "5",
        "ratingValue": "3.5",
        "worstRating": "1"
      }
    },
    {
      "@type": "Review",
      "author": "Wario",
      "datePublished": "2020-07-11",
      "reviewBody": "Exactly what I was looking for!",
      "name": "Perfect!",
      "reviewRating": {
        "@type": "Rating",
        "bestRating": "5",
        "ratingValue": "5",
        "worstRating": "1"
      }
    }
  ]
}
</script>
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