I think it should be like below(You missed
#topOption td>
before the hover)
#topOption td>a{vertical-align:middle; color:#F8E1AB;text-decoration:none; font-size:small;border:solid 7px black; border-bottom-width:0px; }
#topOption td>a:hover{border:solid 7px white;background-color:#fff;color:Black;font-size:small;}
Simple code is
a
{
background-color:grey;
}
a:hover
{
background-color:yellow;
}