Arc-hive-omeka-theme/asset/scss/global/_branding.scss

.brand-logo,.site-brand {
  .site-name,.site-description {
     display: none;
  }
  &::before {
    content: '';
    display:inline-block;
    margin-top:-$global-padding;
    width: 100%;
    height: $global-padding*5;
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
  }
  .logo {
    @include breakpoint(small){
      max-width: 6rem;
      margin-top: -3rem; //half of .logo size
    }
    @include breakpoint(medium){
      max-width: 10rem;
      margin-top: -5rem; //half of .logo size
    }
  }
  &.arc-hive{
    &::before {
      max-width: 10rem;
      background-image: url('../img/ARC-HIVE-logo.svg');
    }
  }
  &.eu{
    &::before {
      background-image: url('../img/eu_flag_creative_europe_co_funded_left.svg');
    }
  }
}