CSS Only Fullscreen Sliding Navigation Menu

Just another pure CSS/CSS3 burger menu that slides out a fullscreen navigation menu when toggled.

How to use it:

Create a nav list as follow:

<nav>    
  <ul>
    <li><a href="#">Link #1</a></li>
    <li><a href="#">Link #2</a></li>
    <li><a href="#">Link #3</a></li>
  </ul>  
</nav>

The html for the hamburger menu toggle.

<input id="burger" type="checkbox" />
<label for="burger">
    <span></span>
    <span></span>
    <span></span>
</label>

The primary CSS for the hamburger menu toggle.

input + label {
  position: fixed;
  top: 40px;
  right: 40px;
  height: 20px;
  width: 15px;
  z-index: 5;
}
input + label span {
  position: absolute;
  width: 100%;
  height: 2px;
  top: 50%;
  margin-top: -1px;
  left: 0;
  display: block;
  background: #020304;
  transition: .5s;
}
input + label span:first-child { top: 3px; }
input + label span:last-child { top: 16px; }
label:hover { cursor: pointer; }
input:checked + label span {
  opacity: 0;
  top: 50%;
}
input:checked + label span:first-child {
  opacity: 1;
  transform: rotate(405deg);
}
input:checked + label span:last-child {
  opacity: 1;
  transform: rotate(-405deg);
}

Style the navigation menu with the following CSS:

input ~ nav {
  background: white;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100px;
  z-index: 3;
  transition: .5s;
  transition-delay: .5s;
  overflow: hidden;
}
input ~ nav > ul {
  text-align: center;
  position: absolute;
  top: 35%;
  left: 20%;
  right: 20%;
}
input ~ nav > ul > li {
  opacity: 0;
  transition: .5s;
  transition-delay: 0s;
}
input ~ nav > ul > li > a {
  text-decoration: none;
  text-transform: uppercase;
  color: #020304;
  font-weight: 700;
  font-family: sans-serif;
  display: block;
  padding: 30px;
}
input:checked ~ nav {
  height: 100%;
  transition-delay: 0s;
}
input:checked ~ nav > ul > li {
  opacity: 1;
  transition-delay: .5s;
}