Mobile Menu Toggle Button | http://codepen.io/agragregra/pen/bEbbmZ

MenuButton.html

<!-- HTML -->
<a href="#" class="toggle-mnu hidden-lg"><span></span></a>

<!-- CSS -->
body {
  background-color: #333;
}

.toggle-mnu {
  display: block;
  width: 28px;
  height: 28px;
  margin-top: 14px;
}
.toggle-mnu span:after, .toggle-mnu span:before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
}
.toggle-mnu span:after {
  top: 18px;
}
.toggle-mnu span {
  position: relative;
  display: block;
}
.toggle-mnu span, .toggle-mnu span:after, .toggle-mnu span:before {
  width: 100%;
  height: 2px;
  background-color: #fff;
  transition: all 0.3s;
  backface-visibility: hidden;
  border-radius: 2px;
}
.toggle-mnu.on span {
  background-color: transparent;
}
.toggle-mnu.on span:before {
  transform: rotate(45deg) translate(-1px, 0px);
}
.toggle-mnu.on span:after {
  transform: rotate(-45deg) translate(6px, -7px);
}

    
<!-- jQuery -->
$(".toggle-mnu").click(function() {
  $(this).toggleClass("on");
  $(".main-mnu").slideToggle();
  return false;
});