CSS text-align not working - css

Question

I have this css code here
.navigation{
width:100%;
background-color:#7a7a7a;
font-size:18px;
}
.navigation ul {
list-style-type: none;
margin: 0;
}
.navigation li {
float: left;
}
.navigation ul a {
color: #ffffff;
display: block;
padding: 0 65px 0 0;
text-decoration: none;
}
What I am trying to do is center my class navigation. I tried using text-align:center; and vertical-align:middle; but neither of them worked.
and here is the HTML Code
<div class="navigation">
<ul>
<li>home</li>
<li>about</li>
<li>tutors</li>
<li>students</li>
<li>contact us</li>
</ul>
</div><!--navigation-->
When I say its not working, I mean the text is aligned to the left.

Answer 1

Change the rule on your <a> element from:
.navigation ul a {
color: #000;
display: block;
padding: 0 65px 0 0;
text-decoration: none;
}​
to
.navigation ul a {
color: #000;
display: block;
padding: 0 65px 0 0;
text-decoration: none;
width:100%;
text-align:center;
}​
Just add two new rules (width:100%; and text-align:center;). You need to make the anchor expand to take up the full width of the list item and then text-align center it.
jsFiddle example

Answer 2

You have to make the UL inside the div behave like a block. Try adding
.navigation ul {
display: inline-block;
}

Answer 3

I try to avoid floating elements unless the design really needs it. Because you have floated the <li> they are out of normal flow.
If you add .navigation { text-align:center; } and change .navigation li { float: left; } to .navigation li { display: inline-block; } then entire navigation will be centred.
One caveat to this approach is that display: inline-block; is not supported in IE6 and needs a workaround to make it work in IE7.