<header>
  
  <div class="hamburger-icon" id="icon">
    <div class="icon-1" id="a"></div>
    <div class="icon-2" id="b"></div>
    <div class="icon-3" id="c"></div>
    <div class="clear"></div>
  </div>
  
  <nav id="nav">
     
    <ul>
      <li>HOme</li>
      <li>About</li>
      <li>Contact</li>
      <li>Help</li>
    </ul>
  
  </nav>
  
  <div class="dark-blue" id="blue"></div>
  
  <section class="content">
    <h1>Hello We are animated!</h1>
    <p class="small">Lorem ipsum dolor sit amet</p>
  </section>
</header>

@import url(https://fonts.googleapis.com/css?family=Montserrat:400,700);

body {
  font-family: 'montserrat',roboto;
}
header {
  width: 100%;
  height: 100%;
  background: #e74c3c;
  position: absolute;
  overflow: auto;
}

.icon-1, .icon-2, .icon-3 {
    position: absolute;
    left: 25%;
    top: 50%;
    width: 32px;
    height: 3px;
    background-color: black;
    transition: all 400ms cubic-bezier(.84,.06,.52,1.8);
}

.icon-1 {
  transform: translateY(-8px);
  animation-delay: 100ms;
}

.icon-3 {
  transform: translateY(8px);
  animation-delay: 250ms;
}

.hamburger-icon {
  position: absolute;
  height: 60px;
  width: 60px;
  top: 10%;
  left: 3%;
  z-index: 1000;
  cursor: pointer;
  border-radius: 50%;
  transition: all 0.2s ease-in-out;
  background: rgba(255,255,255,0.2);
  // background: green;
  // width: auto;
  // height: 50px;
  // overflow: hidden;
  &:hover {
    // .icon-1 {
    //   transform: rotate(40deg);
    // }
    // .icon-3 {
    //   transform: rotate(-40deg);
    // }
    // .icon-2 {
    //   opacity: 0;
    // }
    transform: scale(1.2);
    box-shadow: 0px 0px 30px rgba(0,0,0,0.1);
  }
}

.icon-1.a {
  transform: rotate(40deg);
}
.icon-3.b {
  transform: rotate(-40deg);
}
.icon-2.c {
  opacity: 0;
}

.clear {
  clear: both;
}

@keyframes slideIn {
  0% {
    width: 0%;
    // transform: scale(.3);
    opacity: 0;
  }
  
  100% {
    width: 50%;
    // transform:scale(1);
    opacity: 1;
  }
}

nav {
  background: #0288D1;
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 0%;
  z-index: 10;
  opacity: 0;
 
    transition: all 600ms cubic-bezier(.62,.04,.3,1.56);
   transition-delay: 100ms;
  ul {
    margin: 0;
    position: absolute;
    top: 30%;
    left: 40%;
    li {
      list-style: none;
      font-size: 24px;
      color: #fff;
      line-height: 2.2;
      text-transform: uppercase;
      letter-spacing: 1.7px;
      
      &:before {
        
      }
    }
  }
}

 nav.show {
  //  opacity: 0;
  // animation: slideIn 0.6s cubic-bezier(.62,.04,.3,1.56);
  // animation-fill-mode: forwards;
   width: 50%;
    // transform:scale(1);
   opacity: 1;
}


.dark-blue {
  position: absolute;
  top: 0;
  left: 0;
  background: #64B5F6;
  height: 100%;
  width: 0%;
  transition: all 500ms cubic-bezier(.62,.04,.3,1.8);
  transition-delay: 50ms;
  z-index: 5;
  opacity: 1;
}

.dark-blue.slide {
  width: 50%;
  opacity: 1;
}

@keyframes shotup {
  0% {
    transform: translateY(300%) ;
    opacity: 0;
  }
  90% {
    transform: translateY(-50px);
  }
  100% {
    transform: translateY(0%) ;
    opacity: 1;
  }
}

.content {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 100%;
  transform: translate(-50%, -50%);
  text-align: center;
  h1 {
    font-size: 70px;
     animation: shotup 600ms ease-in-out;
    animation-delay: 300ms;
  }
}

var icon = document.getElementById("icon");
var icon1 = document.getElementById("a");
var icon2 = document.getElementById("b");
var icon3 = document.getElementById("c");
var nav = document.getElementById('nav');
var blue = document.getElementById("blue");

icon.addEventListener('click', function() {
  icon1.classList.toggle('a');
  icon2.classList.toggle('c');
  icon3.classList.toggle('b');
  nav.classList.toggle('show');
  blue.classList.toggle('slide');
});