Exanding Hamburger Navigation With JavaScript And CSS3

An awesome navigation system that expands the hamburger toggle button into a horizontal navigation bar using CSS3 transitions and transforms.

How to use it:

Create the HTML for the hamburger navigation.

<div class="nav-wrapper">
  <nav>
    <div class="navigation">
      <ul class="nav-items">
        <li><a href="#">Home</a></li>
        <li><a href="#">Portfolio</a></li>
        <li><a href="#">About</a></li>
      </ul>
      <div class="nav-toogler"></div>
    </div>
  </nav>
</div>

The necessary CSS/CSS3. Copy and paste the following CSS snippets into the document.

.nav-wrapper{
  position: relative;
  width: 100%;
  height: 100%;
  font-family: "Trebuchet MS" , Arial;
}
.nav-wrapper::before,
.nav-wrapper::after{
  content: '';
  position: relative;
  display: block;
  width: 100%;
  height: 50%;
  background-color: #EAFBFF;
}
.nav-wrapper::after{
  background-color: #208FF9;
}
.nav-wrapper nav{
  position: absolute;
  top: 0;
  z-index: 1;
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}
.navigation{
  max-width: 500px;
  border-radius: 8px;
  box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.12), 0 1px 5px 0 rgba(0, 0, 0, 0.2);
  background-color: #fff;
  padding-right: 30px;
  line-height: 3;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.nav-wrapper ul{
  display: flex;
  justify-content: space-between;
  list-style: none;
  width: 0;
  overflow: hidden;
  transition: .4s cubic-bezier(.77,0,.18,1);
}
.nav-wrapper.active ul{
  width: 420px;
  margin-right: 20px;
}
a{
  color: #888;
  text-decoration: none;
  transition: .3s;
}
a:hover{
  color: #3C9DFB;
}
.nav-toogler{
  position: relative;
  display: inline-block;
  width: 40px;
  height: 48px;
  padding: 14px 5px;
  cursor: pointer;
}
.nav-wrapper:not(.active) .nav-toogler{
  margin-left: -10px;
}
.nav-toogler::before,
.nav-toogler::after{
  content: '';
  position: relative;
  display: block;
  width: 30px;
  height: 3px;
  background-color: #3C9DFB;
  transition: .4s cubic-bezier(.77,0,.18,1);
}
.nav-toogler::after {
  margin-top: 10px;
}
.nav-wrapper.active .nav-toogler::before,
.nav-wrapper.active .nav-toogler::after{
  position: absolute;
  top: 50%;
  background-color: #3C9DFB;
  transform: rotate(135deg);
}
.nav-wrapper.active .nav-toogler::after {
  transform: rotate(-135deg);
  margin-top: 0;
}

The necessary JavaScript to toggle CSS classes on click.

let navWrapper = document.querySelector('.nav-wrapper'),
    navToogler =  document.querySelector('.nav-toogler')
navToogler.addEventListener('click', function (event) {
  navWrapper.classList.toggle('active')
})