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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>

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

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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

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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 

              
                <main class="D R">
  <article>
   <h1>Article with a Headline</h1>
    <img src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/10558/manwithacamera.jpg" alt="test image" />
    <p> Nullam bibendum hendrerit augue, sed tempus odio sagittis nec. Ut ipsum lorem, scelerisque ac vestibulum et, tincidunt eget urna. Phasellus pellentesque nec urna id elementum. Maecenas a urna metus. Vivamus ac euismod ante. Vivamus ut risus porttitor, porttitor ligula a, maximus risus. Donec maximus vulputate mauris, vel placerat diam interdum eu. Nam tempus diam eget blandit efficitur. Etiam sed porta nisi. Donec sit amet sapien in est pellentesque sollicitudin. Donec nec erat efficitur, efficitur purus vel, vehicula odio. Fusce eget placerat massa, vel porta lacus. Proin consectetur finibus lacinia. </p>
  </article>

  <aside>
    <h2>Sidebar Headlinnne</h2>
    <p>Lorem ipsum dolor sit amet consectetur adipiscing, elit inceptos nunc et litora, cras class id morbi viverra. Leo in hac vel sed molestie fringilla fusce orci, dis nibh pharetra quisque inceptos interdum tortor, porta parturient varius magna curae feugiat vestibulum egestas, suscipit facilisi accumsan torquent aptent lobortis. Non dictum feugiat himenaeos consequat per odio ante porta eget senectus, ac accumsan ligula laoreet vivamus sociis mollis habitasse magna, felis massa dis id malesuada donec ut pulvinar iaculis.</p>
  </aside>
  <footer></footer>
  <footer></footer>
</main>
!

CSS 

              
                * { box-sizing: border-box; } 
h1, h2, p, img { border: solid 8px #c429c4; }
main { border: solid 8px #20a0ca; font-family: "Avenir Next"; margin: 2rem; }
article, aside { border: solid 8px #ffb53e; }
h1 { font-family: "Avenir Next Condensed"; font-weight: 200; font-size: 3.6rem; line-height: 1.1; margin: 0 0 0.5em; }
h2 { text-align:center; margin-top: 0; }

.A {
  display: grid;
  grid-template-columns: 3fr 1fr;
  grid-gap: 0 2rem;
  img {
    width: 300px;
  }
  footer:nth-of-type(1)::after { content: '3fr'; }
  footer:nth-of-type(2)::after { content: '1fr'; }
}

.B {
  display: grid;
  grid-template-columns: 3fr 300px;
  grid-gap: 0 2rem;
  img {
    width: 300px;
  }
  footer:nth-of-type(1)::after { content: '3fr'; }
  footer:nth-of-type(2)::after { content: '300px'; }
}

.C {
  display: grid;
  grid-template-columns: 3fr 300px;
  grid-gap: 0 2rem;
  img {
    width: 100%;
  }
  footer:nth-of-type(1)::after { content: '3fr'; }
  footer:nth-of-type(2)::after { content: '300px'; }
}

.D {
  display: grid;
  grid-template-columns: 3fr 300px;
  grid-gap: 0 2rem;
  img {
    width: 100%;
    height: 50vh; 
    object-fit: cover;
    object-position: 50% 40%;
  }
  footer:nth-of-type(1)::after { content: '3fr'; }
  footer:nth-of-type(2)::after { content: '300px'; }
}

.R {
  border: none;
  h1, h2, p, img { border: none; }
  h2 { font-weight: normal; }
  article, aside { border: none; }
  footer { display: none; }
}

footer {
  text-align: center;
  background: black;
  color: yellow;
  padding: 0.2rem;
  font-size: 1.8rem;
  font-weight: bold;
}
footer:nth-of-type(1) {
  grid-area: 1 / 1 / 2 / 2;
  align-self: center;
}
footer:nth-of-type(2) {
  grid-area: 1 / 2 / 2 / 3;
  align-self: center;
}
!

JS
!
999px

Console