.sidebar-active #sidebar-dimmer {
  opacity: .7;
  -webkit-transform: translateX(-150%);
  transform: translateX(-150%);
  transition: opacity .2s;
}

#sidebar-dimmer {
  display: none;
  position: absolute;
  top: 0;
  left: 100%;
  width: 200%;
  height: 100%;
  background: #000;
  opacity: 0;
  transition: opacity .2s,transform 0s .2s;
  +mobile() {
    display: block;
  }
}