/* DRUPAL TABS Skin */
ul.primary li.active a,ul.primary li a, ul.tabs a,ul.primary  {border:none;}
ul.primary, ul.tabs,#contentBodyWrapper ul.primary {margin:0; padding:0;}
ul.primary {border-bottom:1px solid #ccc; display:block; height:25px; text-align:right;}
ul.primary li {display:inline-block;}
ul.primary li a {margin:0;}
ul.primary li a,ul.primary li.active a {padding:5px 10px; border:1px solid #ccc; display:block;}
ul.secondary {border:none; display:block; height:20px;}
ul.secondary li {display:inline-block;}adding:5px 10px; border:1px solid #ccc;}

Drupal Admin Tabs

drupal

CSS