@media(max-width: 1200px) {
  .desktop {
    display: none;
  }
  
  .mobile {
    display: block;
    border: 1px solid red;
  }
}

@media(min-width: 1201px) {
  .desktop {
    display: block;
    border: 1px solid cyan;
  }
  
  .mobile {
    display: none;
  }
}