.slider {
  /* line them up horizontally */
  display: flex;

  /* allow for scrolling */
  overflow-x: auto;

  /* make it smooth on iOS */
  -webkit-overflow-scrolling: touch;
  scroll-snap-points-x: repeat(300px);
  scroll-snap-type: mandatory;
}
.slider > div {
  /* make sure the width is honored */
  flex-shrink: 0;
  width: 50%;
  height: 50%;
  line-height: 300px;
  text-align: center;
  background: #000000;
  margin-right: 10px;
  border-radius: 5px;
}