Animated Toggle Menu With JavaScript and CSS3

A modern animated toggle menu built with JavaScript and CSS3 transitions & transforms.

How to use it:

1. Create a nav list with a toggle button on the page.

<nav class="active" id="nav">
  <ul>
    <li><a href="#">Home</a></li>
    <li><a href="#">Works</a></li>
    <li><a href="#">About</a></li>
    <li><a href="#">Contact</a></li>
  </ul>
  <button class="icon" id="toggle">
    <div class="line line1"></div>
    <div class="line line2"></div>
  </button>
</nav>

2. The main CSS for the toggle menu.

nav {
  background-color: white;
  padding: 20px;
  width: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 3px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.3);
  transition: width 0.6s linear;
}
nav.active {
  width: 350px;
}
nav ul {
  display: flex;
  list-style: none;
  padding: 0;
  margin: 0;
  width: 0;
  transition: width 0.6s linear;
}
nav.active ul {
  width: 100%;
}
nav ul li {
  transform: rotateY(0deg);
  opacity: 0;
  transition: transform 0.6s linear, opacity 0.6s linear;
}
nav.active ul li {
  opacity: 1;
  transform: rotateY(360deg);
}
nav ul a {
  position: relative;
  color: black;
  text-decoration: none;
  margin: 0 10px;
}

3. Style the toggle button.

.icon {
  background-color: white;
  border: none;
  cursor: pointer;
  position: relative;
  height: 30px;
  width: 30px;
}
.icon:focus {
  outline: none;
}
.icon .line {
  background-color: #5290f9;
  height: 2px;
  width: 20px;
  position: absolute;
  top: 10px;
  left: 5px;
  transition: transform 0.6s linear;
}
.icon .line2 {
  top: auto;
  bottom: 10px;
}
nav.active .icon .line1 {
  transform: rotate(-765deg) translateY(5.5px);
}
nav.active .icon .line2 {
  transform: rotate(765deg) translateY(-5.5px);
}

4. Enable the toggle button to expand & collapse the menu.

const toggle = document.getElementById('toggle');
const nav = document.getElementById('nav');
toggle.addEventListener('click', () => {
    nav.classList.toggle('active')
});