Hamburger_Menu.css

body
 {
   margin: 0;
   padding: 0;
   background:  rgb(0, 60, 139);
   color: white;
   font-family: "Avenir Next", "Avenir", sans-serif;
 }
 
 #menuToggle
 {
   display: block;
   position: relative;
   top: 50px;
   left: 50px;
   
   z-index: 1;
   
   -webkit-user-select: none;
   user-select: none;
 }
 
 #menuToggle a
 {
   text-decoration: none;
   color: white;
   
   transition: color 0.3s ease;
 }
 
 #menuToggle input
 {
   display: block;
   width: 40px;
   height: 32px;
   position: absolute;
   top: -7px;
   left: -5px;
   
   cursor: pointer;
   
   opacity: 0;
   z-index: 2;
   
   -webkit-touch-callout: none;
 }

 #menuToggle span
 {
   display: block;
   width: 33px;
   height: 4px;
   margin-bottom: 5px;
   position: relative;
   
   background: white;
   border-radius: 3px;
   
   z-index: 1;
   
   transform-origin: 4px 0px;
   
   transition: transform 0.5s cubic-bezier(0.77,0.2,0.05,1.0),
               background 0.5s cubic-bezier(0.77,0.2,0.05,1.0),
               opacity 0.55s ease;
 }
 
 #menuToggle span:first-child
 {
   transform-origin: 0% 0%;
 }
 
 #menuToggle span:nth-last-child(2)
 {
   transform-origin: 0% 100%;
 }
 
 #menuToggle input:checked ~ span
 {
   opacity: 1;
   transform: rotate(45deg) translate(-2px, -1px);
   background: white;
 }
 
 #menuToggle input:checked ~ span:nth-last-child(3)
 {
   opacity: 0;
   transform: rotate(0deg) scale(0.2, 0.2);
 }
 
 #menuToggle input:checked ~ span:nth-last-child(2)
 {
   transform: rotate(-45deg) translate(0, -1px);
 }
 
 #menu
 {
   position: absolute;
   width: 300px;
   margin: -100px 0 0 -50px;
   padding: 50px;
   padding-top: 125px;
   
   background:  rgb(0, 60, 139);
   list-style-type: none;
   -webkit-font-smoothing: antialiased;
   transform-origin: 0% 0%;
   transform: translate(-100%, 0);
   
   transition: transform 0.5s cubic-bezier(0.77,0.2,0.05,1.0);
 }
 
 #menu li
 {
   padding: 10px 0;
   font-size: 22px;
 }
 
 #menuToggle input:checked ~ ul
 {
   transform: none;
 }