.hamburger {
  position: relative;
  float:left;
  overflow: hidden;
  padding: 0;
  margin-bottom:10px;
  width: 20px;
  height: 24px;
  font-size: 0;
  text-indent: -9999px;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  box-shadow: none;
  border-radius: none;
  border: none;
  cursor: pointer;
background-color: transparent;
}

.hamburger:focus {
  outline: none;
}

.hamburger span {
  display: block;
  position: absolute;
  top: 9px;
  left: 0;
  right: 0;
  height: 2px;
  background: #777;
}

.hamburger span::before,
.hamburger span::after {
  content: "";
  position: absolute;
  display: block;
  left: 0;
  width: 100%;
  height: 2px;
  background: #777;
}

.hamburger span::before {top: -6px;}
.hamburger span::after {bottom: -6px;}


/* active state, i.e. menu open */
.hamburger.is-active {background-color:transparent;}
.hamburger.is-active span {background: none;}

.hamburger.is-active span::before,.hamburger.is-active span::after {
  top: 50%;
  -webkit-transform: rotate(45deg);
      -ms-transform: rotate(45deg);
          transform: rotate(45deg);
}

.hamburger.is-active span::after {
  top: 50%;
  -webkit-transform: rotate(-45deg);
      -ms-transform: rotate(-45deg);
          transform: rotate(-45deg);
}