Question

How come both links get bold with this setup?

I would like that only the a-tag just below the li.current get bold.

CSS

.ul li.current a:first-child{
    font-weight:bold;
}

Html

<ul>
  <li class="current">
    <a href="">This link</a>
      <ul>
        <li>
          <a href="">Not this</a>
        </li>
      </ul>
  </li>
</ul>

Answer 1

Use:

ul li.current > a:first-child{
    font-weight:bold;
}

jsFiddle example

The > refers to the immediate child. So while your rule was being applied to any anchor that was a child, the above rule only applies to the immediate children of ul li.current. Note that you may also be able to drop the :first-child part depending on how you want your links formatted.

Also note that in your code you have .ul where you probably just wanted ul as is in my example.