Optimizing load time in CSS for nested list items - css

Question

I'm creating a sidenav that has some major links that lead to a list of lesser links. A few of the lesser links are listed after the major links. Should I:
format the html like
<ul id="whatever">
<li id="child">
</li>
<li id="descendent">
</li>
</ul>
and use a ul id child selector;
or format the html like
<ul>
<li class="major">
</li>
<li class="minor">
</li>
</ul>
and use a li class selector;
or format the html like
<div class="left nav-major">
<ul>
<li>
</li>
</div>
<div class="left nav-minor">
<li>
</li>
</ul>
</div>
and use div selectors;
or do something else?
If I should do something else, what should it be?
Obviously, I'm trying to optimized load time.

Answer 1

CSS doesnt' really affect load time aside from how large your CSS file is.
In your examples, the first and second are exactly the same in terms of the HTML structure.
The 3rd example is not valid markup.
If you want to optimize load time, use the least amount of markup and CSS as you can.
That said, don't go overboard. There's a pragmatic middle-ground as you want to keep the markup semantic and human readable to make it maintainable.
Since a navigation list is typically a list of links, lists seem appropriate:
<ul>
<li>Main level link
<ul>
<li>Child level link</li>
</ul>
</li>
</ul>
And there'd be no need for classes, as you could reference the levels in your css as:
.navigation li {style main level links}
.navigation li li {style secondary level links}