Making CSS rules for links in header more DRY
The worst aspect of your code is the markup, not the CSS.  Unless you need the div as an actual styling hook, you can safely discard it.  After all, you're not styling it in any meaningful way (what you do have can just as easily be applied to the descendant tags).

&lt;div class="header"&gt;
    &lt;a href="/" class="headerLogo"&gt;BruxZir&lt;/a&gt;
    &lt;a href="#" class="headerMenu"&gt;&amp;equiv;&lt;/a&gt; &lt;!-- other HTML and JS left out --&gt;
&lt;/div&gt;


However, the inclusion of semantic tags might be a better way to go:

&lt;header&gt;
    &lt;h1&gt;&lt;a href="/" class="logo"&gt;BruxZir&lt;/a&gt;&lt;/h1&gt;
    &lt;nav&gt;
        &lt;a href="#" class="menu"&gt;&amp;equiv;&lt;/a&gt; &lt;!-- other HTML and JS left out --&gt;
    &lt;/nav&gt;
&lt;/header&gt;