/*This puts a solid border around the tabs*/
.RadTabStripTop_Default .rtsLevel .rtsUL .rtsLI 
{
    border:solid 1px black; 
}
/*This one sets the text of selected tab solid*/
.RadTabStripTop_Default .rtsLevel .rtsUL .rtsLI .rtsSelected 
{
    font-weight:bold;
}