Question

How do I modify the css such that only the top items (index items) are centerered, the sub items are fine (as they are already positioned to the left)?

<div id="menu">
<ul>
<li><a href="#nogo">File</a>
<ul>
<li><a href="#nogo">Save</a></li>
<li><a href="#nogo">Link 1-2</a></li>
<li><a href="#nogo">Link 1-3</a></li>
</ul>
</li>
<li><a href="#nogo">Edit</a>
<ul>
<li><a href="#nogo">Link 2-1</a></li>
<li><a href="#nogo">Link 2-2</a></li>
<li><a href="#nogo">Link 2-3</a></li>
</ul>
</li>
<li><a href="#nogo">View</a>
<ul>
<li><a href="#nogo">Link 3-1</a></li>
<li><a href="#nogo">Link 3-2</a></li>
<li><a href="#nogo">Link 3-3</a></li>
</ul>
</li>
</ul>
</div>

/*HORIZONTAL DROP-DOWN MENU */
#menu{
padding:0;
margin:0;
position: fixed;
top: 33px;
left: 0px;
font-size: 8pt;
}
#menu ul{
padding:0;
margin:0;
}
#menu li{
position: relative;
float: left;
list-style: none;
margin: 0;
padding:0;
} 

#menu li a{
width:120px;
height: 20px;
display: block;
text-decoration:none;
line-height: 20px;
background-color: #A9BBD3;
color: #FFF;
} 

#menu li a:hover{
background-color: #446087;
} 

#menu ul ul{
position: absolute;
top: 20px;
visibility: hidden;
}

#menu ul li:hover ul{
visibility:visible;
}

Answer 1

Easiest way it to target the top level specifically using the > CSS child combinator.

jsFiddle example

#menu > ul > li > a{
    text-align:center;
}

Adding this rule will center the top level text while leaving the sub-menu text left justified.