Hi,
Slight change to your code,
#nav {
width: 100%;
float: left;
margin: 0 0 3em 0;
padding: 0;
text-align:center;
list-style: none;
background-color: #f2f2f2;
border-bottom: 1px solid #ccc;
border-top: 1px solid #ccc;
}
#nav li {
display:inline;
}
#nav li a {
display: block;
padding: 8px 15px;
text-decoration: none;
font-weight: bold;
color: #069;
border-right: 1px solid #ccc;
}
#nav li a:hover {
color: #c00;
background-color: #fff;
}
Hope this is what you expected..