.header-two {
  background: url("../img/minli/minli-banner2.png") no-repeat center center;
  background-size: cover;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  width: 100%;
  height: 100%; /* For at least Firefox */
  position: relative;
}
@media (max-width: 768px) {
  /* Adjust this breakpoint as needed */
  .header-two {
    background-size: contain;
    height: 22em;
  }
}