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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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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).

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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 

              
                <div class="spacer"></div> <!-- Container before the splitscreen -->

<div id="wrapper">
  <div class="container left">
    <div id="bgImage"></div>
  </div>
  <div class="container right">
    <div class="message" id="message1">Message 1</div>
    <div class="message" id="message2">Message 2</div>
    <div class="message" id="message3">Message 3</div>
  </div>
</div>

<div class="spacer"></div> <!-- Container after the splitscreen -->
!

CSS 

              
                body,
html {
  margin: 0;
  padding: 0;
}

.spacer {
  height: 100vh;
  background-color: #d0d0d0;
}

#wrapper {
  display: flex;
  height: 300vh;
}

.container {
  width: 50%;
  height: 100vh;
  position: relative;
  overflow: hidden;
}

.left #bgImage {
  background: url("https://images.pexels.com/photos/3222686/pexels-photo-3222686.jpeg")
    no-repeat bottom center;
  background-size: cover;
  width: 100%;
  height: 300%;
  position: absolute;
  transform-origin: center center;
  transform: scale(3);
}

.right .message {
  width: 100%;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  opacity: 0;
  position: absolute;
  top: 0;
  left: 0;
}
!

JS 

              
                gsap.registerPlugin(ScrollTrigger);

// Scaling down and pinning the background image on the left
gsap.to("#bgImage", {
  scale: 1,
  scrollTrigger: {
    trigger: ".left",
    pin: true,
    start: "top top",
    end: "+=200%",
    scrub: true
  }
});

// Fading in the messages on the right
const messages = gsap.utils.toArray(".message");
messages.forEach((message, index) => {
  gsap
    .timeline({
      scrollTrigger: {
        trigger: message,
        start: `top+=${index * 100}vh top`,
        end: `+=100vh`,
        pin: true,
        pinSpacing: "none",
        scrub: true
      }
    })
    .fromTo(message, { opacity: 0 }, { opacity: 1, duration: 0.5 }, "start") // Fades in the message
    .fromTo(message, { opacity: 1 }, { opacity: 0, duration: 0.5 }, "end-=0.5"); // Fades out the message
});
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999px

Console