You’ve got more issues than simple CSS... try running that page through the validator for starters. Typically you don’t want content after the closing body tag.
Also, your sample did not reflect the actual code output on your site:
<div id="navbar">
<ul><li><a href="/index.html" title="???????" >???????</a></li>
<li><a href="/news.html" title="???????" >???????</a></li>
<li><a href="/articles.html" title="??????" >??????</a></li>
<li class="current"><a href="/credit.html" title="??????" >??????</a></li>
<li><a href="/shop.html" title="???????" >???????</a></li>
<li><a href="/support.html" title="?????????" >?????????</a></li>
<li><a href="/about.html" title="? ????????" >? ????????</a></li>
<li><a href="/blog.html" title="????" >????</a></li>
<li class="last"><a href="/forum.html" title="?????" >?????</a></li>
</ul>
The proper selector is how Kyle originally had it until I altered it to match your code sample:
#navbar li.current a {
background: #0183CE;
}
The CSS you were using would never match anything, ergo it’d not render anything. Hope this helps!