.carousel {
  max-width: 100%;
  margin: 0 auto;
  display: flex;
}

@media (min-width: 768px) {
  .carousel {
    max-width: 80%;
    margin: 0 auto;
    display: flex;
  }
}
#imagen {
  width: 100%;
  height: 400px;
  background-size: cover;
}