@import url('common.css') only screen and (min-width: 481px);
@import url('common.mobile.css') only screen and (min-width: 200px) and
  (max-width: 480px);

@media only screen and (min-width: 481px) {
  #header {
    height: 480px;
  }
}

@media only screen and (max-width: 480px) and (min-width: 200px) {
  #header {
    height: 250px;
  }
}