body {
  background-color: hsl(0, 0%, 90%);
}
.slider {
  position: relative;
  width: 400px;
  margin: 40px auto;
  overflow: hidden;
  border: black solid 2px;
  border-radius: 5px;
}

.slider img {
  width: 100%;
  display: none;
}

img.displaySlide {
  display: block;
  animation-name: fade;
  animation-duration: 1.5s;
}

.slider button {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  font-size: 2rem;
  padding: 10px 15px;
  background-color: hsl(0, 0%, 0%, 0.5);
  color: white;
  border: none;
  cursor: pointer;
}

.previous {
  left: 0;
}

.next {
  right: 0;
}

@keyframes fade {
  from {
    opacity: 0.5;
  }
  to {
    opacity: 1;
  }
}