CSS

#miniflex {
width: 100%;
float: left;
font-size: small; /* could be specified at a higher level */
margin: 0;
padding: 0 10px 0 10px;
border-bottom: 1px solid #333;
}

#miniflex li {
float: left;
margin: 0;
padding: 0;
display: inline;
list-style: none;
}

#miniflex a:link, #miniflex a:visited {
float: left;
font-size: 85%;
line-height: 20px;
font-weight: bold;
margin: 0 10px 0 10px;
text-decoration: none;
color: #999;
}

#miniflex a.active:link, #miniflex a.active:visited, #miniflex a:hover {
border-bottom: 4px solid #333;
padding-bottom: 2px;
color: #333;
}

HTML

<ul id="miniflex">
<li><a href="#">brie</a></li>
<li><a href="#" class="active">cheddar</a></li>
<li><a href="#">gorgonzola</a></li>
<li><a href="#">colby</a></li>
<li><a href="#">ricotta</a></li>
<li><a href="#">mascarpone</a></li>
</ul>