.drawer {
  position: fixed;
  z-index: 50;
  top: 0;
  bottom: 0;
  transition: .2s all ease;

  background-color: #fff;
  width: 45rem;
  max-width: 90%;
}

.drawer--left {
  left: 0;
  transform: translateX(-100%);
}

.drawer--right {
  right: 0;
  transform: translateX(100%);
}

.drawer--active {
  transform: translateX(0);
  opacity: 1;
}