.main-carousel {
  padding-bottom: 2rem;
}
.carousel-cell {
  width: 100%; /* full width */
  height: 12em; /* height of carousel */
  margin-right: 1rem;
  border-radius: .25rem;
}
@media screen and ( min-width: 768px ) {
  /* half-width cells for larger devices */
  .carousel-cell { width: 25%; }
}