.megamenu-wrapper {
  display: none;
  width: 100%;
}
  .megamenu {
    background: #ccc;
    left: 0;
    position: absolute;
    top: 0;
    width: 100%;
    z-index: 100;
  }

.megamenu-invisible {
  opacity: 0;
  visibility: hidden;
}

.megamenu-underlay {
  background: url(../../../../../themes/interoute/assets/images/all/background-colours/0.5/black.png) repeat;
  background: rgba(0, 0, 0, 0.5);
  display: none;
  height: 100%;
  left: 0;
  position: absolute;
  top: 0;
  width: 100%;
  z-index: 98;
}

.megamenu-menu {
  position: relative;
  z-index: 99;
}