marrs

a {
  display:inline-block;
  text-decoration:none;
  border-bottom: 4px solid blue;
  }

a {
  display:inline-block;
  text-decoration:none;
}
  a:after {
    display:block;
    content:'';
    width:100%;
    height:4px;
    background:blue;
    margin-top:-4px;
  }

header {
  height: 100vh;
  min-height: 600px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

header {
  height: 100vh;
  min-height: 600px;
  position:relative
}
.container-fluid {
  left:0;
  width:100%;
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
}

<?php if( current_user_can('administrator')  ) {  ?> 
    // stuff here for admins
<?php } ?>