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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-.

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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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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 esm.sh, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ESM usage.

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HTML 

              
                <nav>
  <h2>Revealed On Scroll</h2>
</nav>

<main>
  <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Distinctio, repellat atque soluta sequi quae, eaque rem facere necessitatibus vel minus quia excepturi fugit ipsam totam quas eum sed accusamus ut?</p>
  <p>Eaque nobis sequi sint magnam saepe voluptatum velit quam. Sapiente aspernatur repellendus, eius adipisci, rem dolor nobis excepturi consequatur libero vitae dicta officiis sunt ratione. Nemo hic ipsum aperiam aliquam? Eaque nobis sequi sint magnam saepe voluptatum velit quam. Sapiente aspernatur repellendus, eius adipisci, rem dolor nobis excepturi consequatur libero vitae dicta officiis sunt ratione. Nemo hic ipsum aperiam aliquam? Eaque nobis sequi sint magnam saepe voluptatum velit quam. Sapiente aspernatur repellendus, eius adipisci, rem dolor nobis excepturi consequatur libero vitae dicta officiis sunt ratione. Nemo hic ipsum aperiam aliquam?</p>
  <p>Aliquam, aperiam distinctio. Facilis quia totam tempore odio natus minus assumenda iste ab error consequatur, expedita iure et magnam nisi voluptas necessitatibus ipsam, maiores eligendi blanditiis? Temporibus maiores voluptates blanditiis?</p>
  <p>Sint nisi nam aut labore sequi laboriosam voluptates earum debitis, provident minima molestias fugit quidem totam autem dolor! Molestias sequi beatae aut. Fugit et minus velit culpa quasi eos in!</p>
  <p>Nesciunt mollitia doloribus quaerat ratione aliquid quae odit ut sint eaque fugit placeat at, molestiae quo ullam, temporibus dolor. Officia ratione iusto quas dolorum enim eius porro voluptatum veritatis accusantium!</p>
</main>
!

CSS 

              
                @supports (animation-timeline: view()) {
  @keyframes fade-in {
    from { opacity: 0 }
    to   { opacity: 1 }
  }
  
  @keyframes shadow-in {
    to { box-shadow: 0 10px 10px #0003 }
  }
  
  nav, nav > h2 {
    animation: fade-in auto linear both;
    animation-timeline: scroll();
    animation-range: 0% 100px;
  }
  
  nav {
    animation-name: shadow-in;
  }
}

nav {
  position: sticky;
  top: 0;
  z-index: 1;
  background: var(--surface);
  padding: 2rem;
}

html {
  --surface: hsl(200 10% 10%);
  --text: hsl(200 5% 80%);
  
  block-size: 100%;
  inline-size: 100%;
  
  background-color: var(--surface);
  color: var(--text);
}

body {
  min-block-size: 100%;
  min-inline-size: 100%;
  margin: 0;
  padding-block-end: 20vh;
  box-sizing: border-box;
  font-family: system-ui, sans-serif;
}

main {
  max-inline-size: 50ch;
  margin-inline: auto;
}

h2 {
  margin: 0;
  text-align: center;
}

p {
  font-size: 1.25rem;
  line-height: 2;
}
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JS
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999px

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