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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

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

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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

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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 

              
                
<header>
  <h2><code>position: static;</code></h2>
  <p>Nothing to see here, folks. Normal default document flow.</p>
</header>

<section class='static'>
  <div class='a'></div>
  <div class='b'></div>
  <div class='c'></div>
</section>



<header>
  <h2><code>position: sticky;</code></h2>
  <p>Can stay in frame by "sticking" around when scrolled past. Note: you must set place to stick such as <code>top: 0px;</code> or it won't know what to stick to.</p>
</header>

<section class='sticky'>
  <div class='a'></div>
  <div class='b'></div>
  <div class='c'></div>
</section>



<header>
  <h2><code>position: relative;</code></h2>
  <p>Position based on it's natural place in the document flow. It will hold it's place in the flow / but visually move.</p>
  <p>Also, this will team up with absolute positioning.</p>
</header>

<section class='relative'>
  <div class='a'></div>
  <div class='b'></div>
  <div class='c'></div>
</section>



<header>
  <h2><code>position: absolute;</code></h2>
  <p>This will position things based on the closest <em>relative</em>(ly positioned) parent. It will be removed from the document flow.</p>
</header>

<section class='absolute'>
  <div class='a'></div>
  <div class='b'></div>
  <div class='c'></div>
</section>



<header>
  <h2><code>position: fixed;</code></h2>
  <p>Based on the viewport bounderies. It will be removed from the document flow.</p>
  
  <p>You can also change the boundery from the viewport by adding a property like transform to another element and have it behave as the parent context.</p>
</header>

<section class='fixed'>
  <div class='a'></div>
  <div class='b'></div>
  <div class='c'></div>
</section>



<header>
  <h2><code>transform: translate(x, y);</code></h2>
  <p>Translate: ... like relative - but / easier on the rendering engine and smooth to animate! (plus transform can do way more than just move on an X/Y axis)</p>
</header>

<section class='translate'>
  <div class='a'></div>
  <div class='b'></div>
  <div class='c'></div>
</section>
!

CSS 

              
                /* SETUP */
* { 
  box-sizing: border-box; 
}


.b { /* we're highligting this one for some reason */
  border: 2px solid black;
}


.sticky .b {
  position: sticky;
  top: 0;
}

.relative .b {
  top: 20px;
  left: 20px;
}


.absolute {
  position: relative;
}

.absolute .b {
  position: absolute;
  right: -10px;
  bottom: 50px;
}


.fixed .b {
  position: fixed;
  bottom: 0;
  right: 0;
}




/* not really the 'position' property - but you can use it to position things! */
.translate .b {
  transform: translate(20px, 20px);
  transition: 0.5s ease-in-out;
  z-index: 2;
}

.translate:hover .b {
  transform: translate(50px, 50px) scale(1.2) rotate(-370deg);
  box-shadow: 0 3px 10px 0 rgba(0,0,0,.7);
}

















































/* FOR PRESENTATION PURPOSES ONLY */

header {
  margin-top: 60px;
}

body {
  padding: 40px 30px 200px;
}

p {
  max-width: 70ch;
}

div {
  display: inline-block;
  width: 80px;
  height: 80px;
  background-color: lightgray;
}

section {
  min-height: 340px;
  border: 1px solid lightgray;
}

.sticky {
  min-height: 500px;
  /* to make sure it's visibly obvious what is happening */
}

/* TRYING to keep the markup clean and digestable, so - using some tricks to get the letters of the boxes in place  */
div {
  position: relative;
  font-family: sans-serif;
  font-size: 30px;
  color: rgba(0,0,0,.3);
/*   border-radius: 10px; */
  opacity: .9;
}

div:after {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

div.a:after {
  content: "a";
}

div.b:after {
  content: "b";
}

div.c:after {
  content: "c";
}

div.a {
  background-color: var(--pe-orange-light);
}

div.b {
  background-color: var(--pe-orange);
}

div.c {
  background-color: var(--pe-orange-dark);
}


.sticky div.a {
  background-color: var(--pe-green-light);
}
.sticky div.b {
  background-color: var(--pe-green);
}
.sticky div.c {
  background-color: var(--pe-green-dark);
}


.relative div.a {
  background-color: var(--pe-blue-light);
}
.relative div.b {
  background-color: var(--pe-blue);
}
.relative div.c {
  background-color: var(--pe-blue-dark);
}


.absolute div.a {
  background-color: var(--pe-red-light);
}
.absolute div.b {
  background-color: var(--pe-red);
}
.absolute div.c {
  background-color: var(--pe-red-dark);
}


.fixed div.a {
  background-color: var(--pe-yellow-light)
}
.fixed div.b {
  background-color: var(--pe-yellow)
}
.fixed div.c {
  background-color: var(--pe-yellow-dark)
}


.translate div.a {
  background-color: var(--pe-purple-light);
}
.translate div.b {
  background-color: var(--pe-purple);
}
.translate div.c {
  background-color: var(--pe-purple-dark);
}
!

JS
!
999px

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