.slider-outer {
  position: relative;
  width: 40rem;
}

.slider {
  position: relative; 
  z-index: 1;
}

.slide img {
  display: block;
  width: 40rem;
  height: auto;
}

.prev,
.next {
  position: absolute;
  top: 50%;
  z-index: 2;
  -webkit-transform: translateY(-50%);
          transform: translateY(-50%);
  display: block;
  padding: 0.5rem;
  color: white;
  text-decoration: none;
}

.prev {
  left: 1rem;
}

.next {
  right: 1rem;
}