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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>

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Insecure Resource

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CSS

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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.

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JavaScript

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JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

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Babel includes JSX processing.

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HTML 

              
                <button id="menu-toggle"><i class="fas fa-bars"></i></button>
<nav class="menu" id="menu">
  <ol>
    <li class="menu-item"><a href="#0">Home</a></li>
    <li class="menu-item"><a href="#0">About</a></li>
    <li class="menu-item">
      <a href="#0">Widgets</a>
      <ol class="sub-menu">
        <li class="menu-item"><a href="#0">Big Widgets</a></li>
        <li class="menu-item"><a href="#0">Bigger Widgets</a></li>
        <li class="menu-item"><a href="#0">Huge Widgets</a></li>
      </ol>
    </li>
    <li class="menu-item">
      <a href="#0">Kabobs</a>
      <ol class="sub-menu">
        <li class="menu-item"><a href="#0">Shishkabobs</a></li>
        <li class="menu-item"><a href="#0">BBQ kabobs</a></li>
        <li class="menu-item"><a href="#0">Summer kabobs</a></li>
      </ol>
    </li>
    <li class="menu-item"><a href="#0">Contact</a></li>
  </ol>
</nav>

<p>This is some filler content so you can see the menu in action as you normally would.</p>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc malesuada vehicula augue, non tristique ipsum molestie vel. Fusce a libero ut nisl sollicitudin sodales. Praesent dignissim aliquam dui. Aliquam odio quam, commodo nec scelerisque at, hendrerit ut dolor.</p> 
<p>Sed lobortis urna ac justo placerat, nec ullamcorper nisi tincidunt. Praesent pharetra ut arcu sit amet molestie. Maecenas lobortis, nibh in iaculis dapibus, eros libero iaculis risus, sit amet placerat sapien enim at elit. Quisque porta fermentum nisi suscipit vestibulum.</p> 
<p>Interdum et malesuada fames ac ante ipsum primis in faucibus. In nec elementum enim. Suspendisse vulputate felis massa, ac feugiat metus faucibus quis. Phasellus in felis at turpis porttitor ultrices. Quisque laoreet eleifend consequat.</p>
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CSS 

              
                @import url('https://fonts.googleapis.com/css?family=Roboto');

:root {
  --body-top-spacing: 60px;
  --body-gutter: 20px;
}

body {
  margin: 0;
  padding: var(--body-top-spacing) 0 0;
  font-family: 'Roboto';
  font-size: 18px;
}

#menu-toggle {
  z-index: 100;  
  position: fixed;
  top: 0;
  left: 0;
  padding: 1px var(--body-gutter);
  transform: rotate(0deg);
  transition: transform .3s ease-in-out; 
}

.nav-open #menu-toggle {
  transform: rotate(360deg);
}

.nav-open .menu {
  height: 100%;
  background-color: #333;
  transition: background-color .2s ease 0s;
}

.menu a {
  color: #EEE;
  text-decoration: none;
}

.menu {
  overflow: hidden;
  position: fixed;
  top: 0;
  padding-top: var(--body-top-spacing);
  height: 0;
  width: 100%;
  color: #000;
  background-color: #fff;
  transition: background-color .2s ease, height 0s ease .2s;
  -webkit-font-smoothing: antialiased;
}

ol,
ul {
  margin: 0;
  padding-left: var(--body-gutter);
  list-style-type: none;
}

.menu-item {
  position: relative;
  line-height: 1.4;
  font-size: 23px;
}

ol ol li.menu-item {
  line-height: 0;
  overflow: hidden;
  transition: line-height .4s;
}

ol .menu-item--open ol li.menu-item {
  line-height: 1.4;
}

button {
  border: 0;
  background-color: transparent;
  -webkit-appearance: none;
  font-size: 40px;
  cursor: pointer;
}

.nav-open button {
  color: #fff;
}

.sub-menu__toggle {
  position: absolute;
  top: -3px;
  right: 0;
  font-size: 26px;
  color: #fff;
}

p {
  padding: 0 var(--body-gutter);
  
  &:first-of-type {
    margin-top: 0;
  }
}
!

JS 

              
                const parentMenus = document.querySelectorAll('.sub-menu');
const menuToggle = document.querySelector('#menu-toggle');
const menu = document.querySelector('#menu');

// Variable for tracking whether the menu is displayed or hidden
let isDisplayed = false;

// Loop through the menu and add toggle buttons for all submenus
parentMenus.forEach(function(element) {
  var expandButton = document.createElement('button');  
  expandButton.innerHTML = '+';
  expandButton.dataset.isOpen = 'false';
  expandButton.classList.add('sub-menu__toggle');
  element.parentNode.prepend(expandButton);
});

// Toggle submenu open button being interacted with
const allButtons = document.querySelectorAll('.sub-menu__toggle');
allButtons.forEach(function(el, idx) {
  el.addEventListener('click', function(ev) {
    let subMenuOpen = el.dataset.isOpen;
    if('false' == subMenuOpen) {
      el.innerHTML = '-';
    } else {
      el.innerHTML = '+';
    }
    el.dataset.isOpen = ('true' == subMenuOpen) ? 'false' : 'true';
    el.parentNode.classList.toggle('menu-item--open');
  });
});

// Toggle opening/closing the menu
menuToggle.addEventListener('click', function(event) {
  isDisplayed = !isDisplayed;
  var displayClass = isDisplayed ? 'block' : 'none';
  if(isDisplayed) {
    menuToggle.innerHTML = `<i class="fas fa-times"></i>`;
  } else {
    menuToggle.innerHTML = `<i class="fas fa-bars"></i>`;
  }
  document.body.classList.toggle('nav-open');
});
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999px

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