Select Last of Type with CSS - css

Question

Given the following HTML, what CSS rule would select and ONLY select the line that says TWO?
<ul class="menu">
<li><a>void</a></li>
<li class="active">
<a>one</a>
<ul class="sub-menu">
<li class="active"><a>two</a></li>
<li><a>three</a></li>
</ul>
</li>
</ul>
The following selector doesn't work:
.active:last-of-type {...}
Also, I must clarify that if there is no sub-menu or rather the link in the sub-menu is NOT active, then the parent menu must be selected by the same rule. In other words, given the following HTML, the same rule would highlight the line that says ONE:
<ul class="menu">
<li><a>void</a></li>
<li class="active">
<a>one</a>
<ul class="sub-menu">
<li><a>two</a></li>
<li><a>three</a></li>
</ul>
</li>
</ul>

Answer 1

No single selector statement will match both of your use cases (not until parent selectors are supported, anyway). You would have to include, for example, an additional class in one of those use cases in order to fulfill your requirements without your selector matching all .active elements.
Assuming the following use cases:
Active sub-menu element
<ul class="menu">
<li class="active"><a>one</a></li>
<li>
<ul class="sub-menu">
<li class="active"><a>two</a></li>
<li><a>three</a></li>
</ul>
</li>
</ul>
No active sub-menu element
<ul class="menu no-active-sub-menu">
<li class="active"><a>one</a></li>
<li>
<ul class="sub-menu">
<li><a>two</a></li>
<li><a>three</a></li>
</ul>
</li>
</ul>
The following selectors would work:
.menu .sub-menu > .active,
.menu.no-active-sub-menu > .active {
...
}

Answer 2

ul > ul > li:first-child
but you should nest the child UL inside the li in which case:
ul > li > ul > li:first-child

Answer 3

You can use this
ul ul .active {...}
Going from the code provided

Answer 4

Just use :last-child
ul .active:last-child {
color: green;
}

Answer 5

As was suggested by one of the contributors, the parent required another class to set it apart from the child(ren) menu items for this to work. I am posting my solution in case others are faced with something similar.
This is the HTML when the parent is the active page:
<ul class="menu">
<li><a>void</a></li>
<li class="active">
<a>one (parent, active page)</a>
<ul class="sub-menu">
<li><a>two (child)</a></li>
<li><a>three (child)</a></li>
</ul>
</li>
</ul>
This is the HTML when a child menu item of the parent is the active page:
<ul class="menu">
<li><a>void</a></li>
<li class="active page-parent">
<a>one (parent)</a>
<ul class="sub-menu">
<li class="active"><a>two (child, active page)</a></li>
<li><a>three (child)</a></li>
</ul>
</li>
</ul>
These are the rules I used:
/* Highlights the parent and any child
menu item under the parent when the
parent is the active page. */
ul.menu li.active a {
color: red;
}
/* Keeps the children menu items normal
when the parent is the active page.
Also keeps the parent normal when a
child menu item is the active page. */
ul.menu li.active ul.sub-menu li a,
ul.menu li.active.page-parent a {
color: black;
}
/* Highlights the child menu item that
is active */
ul.menu li.active.page-parent ul.sub-menu li.active a {
color: red;
}
It definitely is straightforward once you identify the parent state with a unique rule when one of its children menu items is active. Obviously, this would be easier if the child items didn't inherit the "active" state from the parent, but the menu system I am using behaves as described here. Thanks to everyone for their contributions.
Note: I have not tested this with a menu containing more than 1 sub-menu level deep.