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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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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.

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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.

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

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

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HTML 

              
                <p id="demo"><span>Silky smooth animations, driven by scroll, running off the main thread … and all that with just a few lines of extra code – What's not to like?!</span></p>

<footer>
  <p>This demo is part of <a href="https://goo.gle/css-wrapped-2023" target="_top">#CSSWrapped2023</a></p>
</footer>
!

CSS 

              
                #demo {
  position: fixed;
  font-size: 1.25em;
  width: 90vw;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);

  text-align: center;
  font-family: Chivo Mono, monospace;

  --chars: 144;
}

span {
  background: 
		/* base color */ #eee /* highlight gradient */
    linear-gradient(to right, #6300ff 0%, #e915c7 100%) 0 / 0 no-repeat;
  -webkit-background-clip: text;
  color: transparent;

  animation: text steps(var(--chars)) forwards;
  animation-timeline: scroll(root);
}

body {
  height: 400dvh;
}

@keyframes text {
  0% {
    background-size: 0ch;
  }
  100% {
    background-size: calc(var(--chars) * 1ch);
  }
}

* {
  margin: 0;
  padding: 0;
}

html {
  font-size: clamp(16px, 2vmax + 1em, 42px);
}

footer {
  position: fixed;
  bottom: 1em;
  left: 0;
  right: 0;
  text-align: center;

  font-family: Syne;
  font-size: 0.5rem;
  text-align: center;
  font-style: italic;
}

html {
  --scrollbar-thumb-color: #e915c7;
  --scrollbar-track-color: #eee;
  scrollbar-color: var(--scrollbar-thumb-color) var(--scrollbar-track-color);
}

@supports not (scrollbar-color: red blue) {
  html::-webkit-scrollbar {
    width: 1em;
  }
  html::-webkit-scrollbar-track {
    background: var(--scrollbar-track-color);
  }
  html::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb-color);
  }
}
!

JS
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999px

Console