sandwich.jade

button.toggle_mnu
  span.sandwich
    span.sw-topper
    span.sw-bottom
    span.sw-footer

sandwich.js

  $(".toggle_mnu").click(function() {
      $(".sandwich").toggleClass("active");
  });

  $(".top_mnu ul a").click(function() {
      $(".top_mnu").fadeOut(600);
      $(".sandwich").toggleClass("active");
      $(".top_text").css("opacity", "1");
  }).append("<span>");

  $(".toggle_mnu").click(function() {
      if ($(".top_mnu").is(":visible")) {
          $(".top_text").css("opacity", "1");
          $(".top_mnu").fadeOut(600);
          $(".top_mnu li a").removeClass("fadeInUp animated");
      } else {
          $(".top_text").css("opacity", ".1");
          $(".top_mnu").fadeIn(600);
          $(".top_mnu li a").addClass("fadeInUp animated");
      };
  });

sandwich.scss

.toggle_mnu{
  display: none;
	width: 40px;
	height: 40px;
	position: fixed;
	z-index: 7600;
	border: none;
	right: 20px;
	top: 20px;
	span{
		display: block;
  }
}

$w: 28px;
$h: 3px;

.sandwich {
	width: $w;
	height: $w;
	position: absolute;
	top: 8px;
	bottom: 0;
	left: 0;
	right: 0;
	margin: auto;
	z-index: 200;
}
.sw-topper{
	position: relative;
	top: 0;
	width: $w;
	height: $h;
	background: rgb(255, 255, 255);
	border: none;
	border-radius: 4px 4px 4px 4px;
	transition: transform 0.5s, top 0.2s;
	display: block;
}
	//transition-delay: 0.2s, 0
.sw-bottom{
	position: relative;
	width: $w;
	height: $h;
	top: $h * 2.2;
	background: rgb(255, 255, 255);
	border: none;
	border-radius: 4px 4px 4px 4px;
	transition: transform 0.5s, top 0.2s;
	transition-delay: 0.2s, 0s;
}
.sw-footer{
	position: relative;
	width: $w;
	height: $h;
	top: $h * 4.5;
	background: rgb(255, 255, 255);
	border: none;
	border-radius: 4px 4px 4px 4px;
	transition: all 0.5s;
	transition-delay: 0.1s;
}
.sandwich.active{
	.sw-topper{
		top: 9px;
		transform: rotate(-45deg);
  }
	.sw-bottom{
		top: 6px;
		transform: rotate(45deg);
  }
	.sw-footer{
		opacity: 0;
		top: 0;
		transform: rotate(180deg);
  }
}