.header {
  margin-bottom: -35px;
}

/* Large devices (desktops, 992px and up) */
@media (max-width: 991.98px) { 
  .header {
      margin-bottom: -15px;
  }
}

/* Small devices (landscape phones, 576px and up) */
@media (max-width: 575.98px) { 
  .header {
      margin-bottom: -35px;
  }
}