/* logical styling */
a#gamburger {
  border: 1px solid rgba(0,40,60,.2);  
}
.open {
  border-color: rgba(255,255,255,.2);
}
span {
  background: rgb(0,40,60);  
  transition: .7s;
}
.open span {
  background: #fff;
}
.open :first-child {
  -webkit-transform: translateY(5px) rotate(-45deg);
  transform: translateY(5px) rotate(-45deg);
}
.open :nth-child(2) {
  -webkit-transform: rotate(-45deg);
  transform: rotate(-45deg);
  opacity: 0;
}
.open :last-child {
  -webkit-transform: translateY(-5px) rotate(-135deg);
  transform: translateY(-5px) rotate(-135deg);
}

/* visual styling */
a#gamburger {
  position: absolute;
  top: 20px;
  left: 20px;
  z-index: 3;
  width: 36px;
  height: 36px;
  box-sizing: border-box;
  padding: 11px 0 0 9px;
  border-radius: 50%;
  -webkit-tap-highlight-color: transparent;
}
span {
  display: block;
  width: 16px;
  height: 2px;
  pointer-events: none;
}
span:nth-child(2) {
  margin: 3px 0;
}

a#gamburger.open {position: fixed;}