Fullscreen Responsive Toggle Menu with Pure JavaScript

An animated, responsive menu system that fills the whole browser screen when toggled. The item text will auto-adapt to fit the menu container as the window’s size changed. Made with Javascript and CSS/CSS3. Created by rachsmith.

How to use it:

Create a hamburg icon for the menu toggle button.

<div id="nav-trigger" class="nav-trigger open">
  <span class="line"></span>
  <span class="line"></span>
  <span class="line"></span>
</div>

The CSS for the toggle button to create an animated  hamburg icon with fancy transitions.

.nav-trigger {
  position: fixed;
  width: 110px;
  height: 98px;
  right: 0px;
  top: 0px;
  cursor: pointer;
  z-index: 200;
  -webkit-transform-origin: 110px 0px;
  -moz-transform-origin: 110px 0px;
  -ms-transform-origin: 110px 0px;
  -o-transform-origin: 110px 0px;
  transform-origin: 110px 0px;
  -webkit-transform: scale(0.6);
  -moz-transform: scale(0.6);
  -ms-transform: scale(0.6);
  -o-transform: scale(0.6);
  transform: scale(0.6);
  -webkit-transition: background 0.3s linear;
  -moz-transition: background 0.3s linear;
  transition: background 0.3s linear;
}
.nav-trigger.open {
  background: #222;
}
.nav-trigger.close {
  background: transparent;
}
.line {
  display: block;
  position: absolute;
  width: 80px;
  height: 8px;
  background: #fff;
  left: 15px;
  -webkit-transform-origin: 0px 4px;
  -moz-transform-origin: 0px 4px;
  -ms-transform-origin: 0px 4px;
  -o-transform-origin: 0px 4px;
  transform-origin: 0px 4px;
  -webkit-transition: opacity 0.3s cubic-bezier(0.645, 0.045, 0.355, 1) 0s, -webkit-transform 0.24s cubic-bezier(0.645, 0.045, 0.355, 1) 0s;
  -moz-transition: opacity 0.3s cubic-bezier(0.645, 0.045, 0.355, 1) 0s, -moz-transform 0.24s cubic-bezier(0.645, 0.045, 0.355, 1) 0s;
  transition: opacity 0.3s cubic-bezier(0.645, 0.045, 0.355, 1) 0s, transform 0.24s cubic-bezier(0.645, 0.045, 0.355, 1) 0s;
}
.line:nth-child(1) {
  top: 16px;
}
.line:nth-child(2) {
  top: 44px;
}
.line:nth-child(3) {
  top: 72px;
}
.close .line:nth-child(1) {
  -webkit-transform: translateX(11px) rotate(45deg);
  -moz-transform: translateX(11px) rotate(45deg);
  -ms-transform: translateX(11px) rotate(45deg);
  -o-transform: translateX(11px) rotate(45deg);
  transform: translateX(11px) rotate(45deg);
}
.close .line:nth-child(2) {
  opacity: 0;
}
.close .line:nth-child(3) {
  -webkit-transform: translateX(11px) rotate(-45deg);
  -moz-transform: translateX(11px) rotate(-45deg);
  -ms-transform: translateX(11px) rotate(-45deg);
  -o-transform: translateX(11px) rotate(-45deg);
  transform: translateX(11px) rotate(-45deg);
}

Create a navigation menu using Html unordered list.

<nav id="nav" class="out">
  <ul>
    <li><span class="nav-label">Home</span></li>
    <li><span class="nav-label">About</span></li>
    <li><span class="nav-label">Work</span></li>
    <li><span class="nav-label">Blog</span></li>
    <li><span class="nav-label">Contact</span></li>
  </ul>
</nav>

The required CSS/CSS3 rules to style the fullscreen nav menu.

nav {
  width: 100%;
  height: 100%;
  position: fixed;
  z-index: 100;
}
nav.out {
  pointer-events: none;
}
nav.in {
  pointer-events: auto;
}
nav ul, li {
  display: block;
  padding: 0;
  margin: 0;
  width: 100%;
  cursor: pointer;
}
nav ul {
  height: 100%;
  width: 100%;
  position: absolute;
}
nav li {
  height: 20%;
  position: relative;
  background: #222;
  color: #fff;
  font-family: "Patua One", cursive;
}
nav li:hover {
  background: #364e41;
}
nav.in li:nth-child(1) {
  -webkit-transition: -webkit-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.1s, opacity 0.5s linear 0.1s;
  -moz-transition: -moz-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.1s, opacity 0.5s linear 0.1s;
  transition: transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.1s, opacity 0.5s linear 0.1s;
}
nav.in li:nth-child(2) {
  -webkit-transition: -webkit-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.2s, opacity 0.5s linear 0.2s;
  -moz-transition: -moz-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.2s, opacity 0.5s linear 0.2s;
  transition: transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.2s, opacity 0.5s linear 0.2s;
}
nav.in li:nth-child(3) {
  -webkit-transition: -webkit-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.3s, opacity 0.5s linear 0.3s;
  -moz-transition: -moz-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.3s, opacity 0.5s linear 0.3s;
  transition: transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.3s, opacity 0.5s linear 0.3s;
}
nav.in li:nth-child(4) {
  -webkit-transition: -webkit-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.4s, opacity 0.5s linear 0.4s;
  -moz-transition: -moz-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.4s, opacity 0.5s linear 0.4s;
  transition: transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.4s, opacity 0.5s linear 0.4s;
}
nav.in li:nth-child(5) {
  -webkit-transition: -webkit-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.5s, opacity 0.5s linear 0.5s;
  -moz-transition: -moz-transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.5s, opacity 0.5s linear 0.5s;
  transition: transform 0.5s cubic-bezier(0.215, 0.61, 0.355, 1) 0.5s, opacity 0.5s linear 0.5s;
}
nav.out li:nth-child(5) {
  -webkit-transition: -webkit-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0s, opacity 0.3s linear 0s;
  -moz-transition: -moz-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0s, opacity 0.3s linear 0s;
  transition: transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0s, opacity 0.3s linear 0s;
}
nav.out li:nth-child(4) {
  -webkit-transition: -webkit-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.05s, opacity 0.3s linear 0.05s;
  -moz-transition: -moz-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.05s, opacity 0.3s linear 0.05s;
  transition: transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.05s, opacity 0.3s linear 0.05s;
}
nav.out li:nth-child(3) {
  -webkit-transition: -webkit-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.1s, opacity 0.3s linear 0.1s;
  -moz-transition: -moz-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.1s, opacity 0.3s linear 0.1s;
  transition: transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.1s, opacity 0.3s linear 0.1s;
}
nav.out li:nth-child(2) {
  -webkit-transition: -webkit-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.15s, opacity 0.3s linear 0.15s;
  -moz-transition: -moz-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.15s, opacity 0.3s linear 0.15s;
  transition: transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.15s, opacity 0.3s linear 0.15s;
}
nav.out li:nth-child(1) {
  -webkit-transition: -webkit-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.2s, opacity 0.3s linear 0.2s;
  -moz-transition: -moz-transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.2s, opacity 0.3s linear 0.2s;
  transition: transform 0.3s cubic-bezier(0.55, 0.055, 0.675, 0.19) 0.2s, opacity 0.3s linear 0.2s;
}
nav.out li {
  -webkit-transform: translateY(300%);
  -moz-transform: translateY(300%);
  -ms-transform: translateY(300%);
  -o-transform: translateY(300%);
  transform: translateY(300%);
  opacity: 0;
}
nav.in li {
  -webkit-transform: translateY(0);
  -moz-transform: translateY(0);
  -ms-transform: translateY(0);
  -o-transform: translateY(0);
  transform: translateY(0);
  opacity: 1;
}
.nav-label {
  position: absolute;
  width: 100%;
  left: 0;
  text-align: center;
  height: 16px;
  top: 50%;
  margin-top: -8px;
  text-transform: uppercase;
}

The Javascript to enable the fullscreen responsive toggle menu.

// selected elements
var navTrigger = document.getElementById('nav-trigger');
var nav = document.getElementById('nav');
var header = document.getElementById('header');
var heading = document.getElementById('heading');
var labels = document.getElementsByClassName('nav-label');
// sizing
var windowHeight = window.innerHeight;
var windowWidth = window.innerWidth;
var fontSize = windowHeight*0.1;
var headingSize = windowWidth*0.1;
resize();
// Event Listening
navTrigger.addEventListener('click', navToggle);
window.addEventListener('resize', resize);
function resize() {
  windowHeight = window.innerHeight;
  windowWidth = window.innerWidth;
  fontSize = windowHeight*0.1;
  headingSize = windowWidth*0.1;
  if(headingSize > windowHeight*0.3) headingSize = windowHeight*0.3; 
  
  for(var i = 0; i < labels.length; i++) {
    labels[i].style.fontSize = fontSize+'px';
    labels[i].style.height = fontSize+'px';
    labels[i].style.marginTop = '-'+fontSize*0.6+'px';
  }
  header.style.height = windowHeight+'px';
  heading.style.fontSize = headingSize+'px';
  heading.style.height = headingSize+'px';
  heading.style.marginTop = '-'+headingSize*0.6+'px';
  
}
function navToggle(e) {
  var closed = (navTrigger.className.indexOf('close') > 0); 
  if(closed) {
    navTrigger.className = 'nav-trigger open';
    nav.className = 'out';
  } else {
    navTrigger.className = 'nav-trigger close';
    nav.className = 'in';
  }
}
window.onload = resize();