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HTML

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Insecure Resource

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CSS

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JavaScript

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Babel includes JSX processing.

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HTML 

              
                <h1>Sample chapter numbering</h1>

<section>
  <h2>first chapter</h2>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce tempor efficitur mi et finibus. Sed cursus arcu vel risus condimentum condimentum at a lectus. Nullam eget nunc libero. Maecenas ultrices efficitur viverra. Mauris ultrices consectetur odio at congue. Donec turpis massa, fermentum semper tortor quis, volutpat consequat purus. Vestibulum ante ipsum, pellentesque nec ultricies vel, auctor placerat sem. Aliquam lacus elit, egestas luctus tellus et, dapibus porttitor ipsum.</p>

  <p>Cras dolor justo, dignissim ut massa cursus, malesuada ornare diam. Duis at sem congue, tempus lorem in, semper odio. Donec interdum condimentum massa ut sollicitudin. Morbi gravida quam eu ante hendrerit, ultrices congue justo accumsan. Suspendisse iaculis ac orci quis porttitor. Sed ac velit ut libero sagittis volutpat id sed ligula. Aliquam ultricies mattis metus, et euismod purus mollis nec. Ut semper justo sed ullamcorper posuere. Fusce quis accumsan massa. Cras in aliquam sem, ut consectetur enim.</p>

  <section>
    <h2>another chapter</h2>
    <p>Suspendisse porta ipsum vitae purus ultricies commodo. Maecenas interdum sem in est scelerisque, quis vestibulum nisi egestas. Phasellus feugiat in est sit amet viverra. Integer pellentesque velit sed commodo finibus. In ipsum ex, fermentum ut ipsum vitae, congue finibus nibh. Vestibulum non magna ex. Donec ut hendrerit urna. Ut ut orci sed lorem tristique varius. Duis egestas augue non massa malesuada tincidunt. Proin in consequat erat, sodales tincidunt diam. Aliquam fringilla commodo ligula, id ullamcorper ligula lobortis ac.</p>
  </section>

  <section>
    <h2>One more, for giggles</h2>
    <p>Aliquam scelerisque justo a cursus rutrum. Aliquam eros libero, gravida vestibulum ex eget, pellentesque ultrices elit. Suspendisse venenatis leo sed nisl bibendum, a ultrices lacus finibus. Praesent a ipsum velit. Suspendisse molestie euismod ligula, mollis volutpat lacus sodales elementum. Mauris at varius magna. Nam sed libero pellentesque, vulputate dui a, feugiat dolor. Donec condimentum nisl sit amet porttitor sollicitudin. Aliquam sagittis quam a felis laoreet, eu aliquam risus faucibus. Suspendisse venenatis, erat vel scelerisque egestas, ipsum lorem imperdiet neque, eu mollis urna velit non metus. Donec accumsan nunc non fermentum congue. Nullam a aliquet leo, nec congue ex. Praesent fringilla vulputate lorem nec laoreet.</p>

    <p>Sed aliquet quam ut odio euismod accumsan. Praesent vitae finibus dolor. Nunc vulputate tortor diam, id lobortis lectus egestas quis. Praesent augue ipsum, congue vel nunc nec, vestibulum mollis risus. Cras rhoncus venenatis ex vel luctus. Cras bibendum maximus finibus. Praesent vel consectetur erat, eu ullamcorper urna. Aenean tempor vehicula ex a dictum. Sed eu tellus in lectus lacinia dapibus. Mauris venenatis vehicula felis, quis scelerisque leo imperdiet sed.
  </section>
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CSS 

              
                body {
  box-sizing: border-box;
  margin: 0 2em;
  font-family: Raleway, Verdana, sans-serif;
  counter-reset: chapter-counter;
}

section p {
  width: 80ch;
}

section {
  counter-increment: chapter-counter;
}

section h2:before {
  content: "Chapter " counter(chapter-counter) ": ";
}
!

JS
!
999px

Console