title: Style <th> with classes in CSS
body: <p>I have some trouble with HTML tables. My table looks like the following:</p>
  
  <pre><code>&lt;table class="shop_table cart" cellspacing="0"&gt;
  &lt;thead&gt;
      &lt;tr&gt;
          &lt;th class="product-remove"&gt;&amp;nbsp;&lt;/th&gt;
          &lt;th class="product-thumbnail"&gt;&amp;nbsp;&lt;/th&gt;
          &lt;th class="product-name"&gt;Produkt&lt;/th&gt;
          &lt;th class="product-price"&gt;Preis&lt;/th&gt;
          &lt;th class="product-quantity"&gt;Anzahl&lt;/th&gt;
          &lt;th class="product-subtotal"&gt;Summe&lt;/th&gt;
      &lt;/tr&gt;
  &lt;/thead&gt;
  &lt;tbody&gt;
  ...
  &lt;/tbody&gt;
  &lt;/table&gt;
  </code></pre>
  
  <p>Now I want to define with CSS that my <code>&lt;th&gt;</code> with all the classes get a <code>border-bottom{1px solid black;}</code>. Important is that only the <code>&lt;th&gt;</code>with the classes are styled, because I have <code>&lt;td&gt;</code>with the same classes and they shouldn't get the border. I hope you can understand me. </p>