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HTML

About HTML Preprocessors

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

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. So you don't have access to higher-up elements like the <html> tag. If you want to add classes there that can affect the whole document, this is the place to do it.

About the <head>

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. If you need things in the <head> of the document, put that code here.

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Insecure Resource

The resource you are linking to is using the 'http' protocol, which may not work when the browser is using https.

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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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

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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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HTML 

              
                <button class="btn" data-toggle="#dialog">Open modal</button>

<button class="btn" data-toggle="#dialog-tall">Open tall modal</button>

<dialog id="dialog">
  <header>
    Example modal
    <button class="btn btn-close" data-close>
      <svg width="16" height="16"><use xlink:href="#x"/></svg>
    </button>
  </header>
  Some basic text inside the modal to demonstrate how it all looks and works.
</dialog>

<dialog id="dialog-tall">
  <header>
    Super tall modal
    <button class="btn btn-close" data-close>
      <svg width="16" height="16"><use xlink:href="#x"/></svg>
    </button>
  </header>
  <p>Line breaks to push the height out.</p>
  <br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>
  <button type="button" class="btn" data-close>Close</button>
</dialog>

<!-- Close button -->
<svg xmlns="http://www.w3.org/2000/svg" style="display: none;">
  <symbol id="x" viewBox="0 0 16 16">
    <path d="m1 1 14 14m0-14-14 14" stroke="currentColor" stroke-width="2"/>
  </symbol>    
</svg>
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CSS 

              
                * {
  box-sizing: border-box;
}

:root {
  --body-color: #333;
  --body-bg: #fff;
  --emphasis-color: #111;
  --accent-color: dodgerblue;
  --secondary-bg: #f5f5f5;
  --border-color: rgba(0,0,0,.15);
  --modal-padding-x: 1.25rem;
  --modal-padding-y: .75rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --body-color: #888;
    --body-bg: #222;
    --emphasis-color: #fff;
    --secondary-bg: #252525;
    --border-color: rgba(255,255,255,.15);
  }
}

html {
  font-size: 16px;
}

body {
  padding: 1.5rem;
  margin: 0;
  font: 1rem/1.5 sans-serif;
  color: var(--body-color);
  background-color: var(--body-bg);
}

.btn {
  display: inline-flex;
  padding: .5rem 1rem;
  margin: 0;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.5;
  color: var(--emphasis-color);
  background: none;
  border: 1px solid var(--border-color);
  border-radius: .375rem;
  box-shadow: 0 .125rem .25rem rgba(0,0,0,.075);
  cursor: pointer;

  &:not(:disabled) {
    &:hover,
    &:focus,
    &:active,
    &[active] {
      color: #fff;
      background-color: var(--accent-color);
      border-color: var(--accent-color);
    }
  }
}

.btn-close {
  padding: .25rem;
  line-height: 1;
  background-color: transparent;
  border: 0;
  border-radius: .25rem;
  box-shadow: none;
}

@keyframes fade-in {
  from {
    opacity: 0;
  } to {
    opacity: 1;
  }
}

dialog {
  position: relative;
  z-index: 100;
  width: 420px;
  max-width: 100%;
  padding: var(--modal-padding-y) var(--modal-padding-x);
  color: var(--body-color);
  background-color: var(--secondary-bg);
  background-clip: padding-box;
  border: 1px solid var(--border-color);
  border-radius: .5rem;
  box-shadow: 0 .5rem 1rem rgba(0,0,0,.5);
  
  &::backdrop {
    background-color: rgba(0,0,0,.5);
    animation: .5s fade-in;
  }
  
  > header {
    position: -webkit-sticky;
    position: sticky;
    top: calc(var(--modal-padding-y) * -1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--modal-padding-y) var(--modal-padding-x);
    margin: calc(var(--modal-padding-y) * -1) calc(var(--modal-padding-x) * -1) var(--modal-padding-y);
    font-weight: 600;
    color: var(--emphasis-color);
    background-color: inherit;
    border-bottom: 1px solid var(--border-color);

    [data-close] {
      margin-right: -.25rem;
    }
  }
}

[open] + .backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(255,0,0,.25);
}
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JS 

              
                let toggler = document.querySelectorAll('[data-toggle]')
let closers = document.querySelectorAll('[data-close]')

if (toggler) {
  toggler.forEach(function (element) {
    let target = element.getAttribute("data-toggle")
    let targets = document.querySelectorAll(target)

    element.addEventListener("click", (event) => {
      targets.forEach(function (e) {
        e.showModal()
      })
    })
  })
  
  closers.forEach(function (element) {
    element.addEventListener("click", (event) => {
      let dialog = element.closest('dialog')
      dialog.close()
    })
  })
}
!
999px

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