Revenge!

Add

.tabdiv > ul {
   border: 0;
   border-bottom: 1px solid #6f6f6f;
   list-style-type: none;
   padding-bottom: 2px;
   margin: 0;
   line-height: 1;
}

.tabdiv > ul a {
   background-color: #eee;
   padding: 2px 1em;
   border: 1px solid #6f6f6f;
   border-bottom: none;
   color: #448;
   margin-right: 0.5em;
   margin-bottom: 0;
}

.tabdiv > ul li {
   display: inline;
   margin: 0;
   margin-bottom: 0; // wiki sets this explicitly
}

.tabdiv > ul li.active {
   background: white;
}

.tabdiv > ul li.active a {
   background: white;
   font-weight: bold;
   position: relative;
   top: 1px;
   padding-top: 3px;
}

.tabdiv > div {
   margin: 0;
   border: 1px solid #6f6f6f;
   border-top: 0;
   padding: 1em 5px 5px 5px;
}

Please and Thank You~