JSFiddle - React, Tailwind, and code Playground

by Andrew Bone

HTML

<nav>
  <ul class="menu">
    <li class="menu__item">
      <a href="/" class="menu__link">About</a>
      <ul class="submenu">
        <li class="submenu__item">
          <a class="submenu__link" href="/our-mission">Our Mission</a>
        </li>
        <li class="submenu__item">
          <a class="submenu__link" href="/our-team">Our Team</a>
        </li>
      </ul>
    </li>
    <li class="menu__item">
      <a href="/" class="menu__link">Contact us</a>
      <ul class="submenu">
        <li class="submenu__item">
          <a class="submenu__link" href="/find-us">On the map</a>
        </li>
        <li class="submenu__item">
          <a class="submenu__link" href="/contact">Send an email</a>
        </li>
        <li class="submenu__item">
          <a class="submenu__link" href="/chat">Live chat</a>
        </li>
      </ul>
    </li>
  </ul>
</nav>

CSS

@import url(http://fonts.googleapis.com/css?family=Open+Sans);
body {
  font-family: "Open Sans";
  margin: 0;
}

nav {
  line-height: 40px;
  align-items: center;
  height: 40px;
  background: #333;
}

.menu {
  margin: 0;
  padding: 0;
  list-style: none;
}

.menu * {
  color: white;
  text-decoration: none;
}

.menu__item {
  position: relative;
  display: inline-block;
  padding: 0 5px;
}

.submenu {
  position: absolute;
  white-space: nowrap;
  min-width: 100%;
  padding: 0;
  margin-left: -5px;
  background: #333;
  list-style: none;
  opacity: 0;
  pointer-events: none;
}

.submenu__item {
  padding: 0 4px;
}

.menu__item:hover .submenu,
.menu__item:focus-within .submenu ,
.menu__item.focus-within .submenu {
  opacity: 1;
  pointer-events: auto;
}

.menu__item:hover,
.menu__item:focus-within,
.menu__item.focus-within,
.submenu__item:hover,
.submenu__item:focus-within{
  background: rgba(255, 255, 255, 0.3)
}

JavaScript

(function(window, document){
	'use strict';
	var slice = [].slice;
	var removeClass = function(elem){
		elem.classList.remove('focus-within');
	};
	var update = (function(){
		var running, last;
		var action = function(){
			var element = document.activeElement;
			running = false;
			if(last !== element){
				last = element;
				slice.call(document.getElementsByClassName('focus-within')).forEach(removeClass);
				while(element && element.classList){
					element.classList.add('focus-within');
					element = element.parentNode;
				}
			}
		};
		return function(){
			if(!running){
				requestAnimationFrame(action);
				running = true;
			}
		};
	})();
	document.addEventListener('focus', update, true);
	document.addEventListener('blur', update, true);
	update();
})(window, document);