title: Horizontal Primary and Sub menu is not align center, why?
body: <p>I'm building simple site from Drupal but the primary and submenu are not aligned center as it should. I have tried many of CSS3 properties but none of them is working.</p>
  
  <p>This is how it structured    </p>
  
  <pre><code>&lt;div class="nav"&gt;
       &lt;ul&gt;
         &lt;li&gt;Primary Menu 1&lt;/li&gt;
         &lt;li&gt;Primary Menu 2&lt;/li&gt;
            &lt;ul&gt;
              &lt;li&gt;Submenu 2.1&lt;/li&gt;
              &lt;li&gt;Submenu 2.2&lt;/li&gt;
            &lt;/ul&gt;
         &lt;li&gt;Primary Menu 3&lt;/li&gt;
         &lt;li&gt;Primary Menu 4&lt;/li&gt;
       &lt;/ul&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>I want to display both of primary and submenu to be horizontal and align center with CSS3, how can I do that, please provide completely new CSS code for me please.</p>
  
  <p>Thank you very much.</p>