title: How to make CSS hover effect persist after clicking Bootstrap button
body: <pre><code>&lt;div class="btn-group"&gt;
      &lt;button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" id="stayBlue"&gt;
          &lt;img src="#"/&gt;
      &lt;/button&gt;
      &lt;ul class="dropdown-menu"&gt;
        &lt;li&gt;&lt;a href="#"&gt;&lt;img src="#" height="32px" width="32px"/&gt;Dropdown link&lt;/a&gt;&lt;/li&gt;
        &lt;li&gt;&lt;a href="#"&gt;&lt;img src="#" height="32px" width="32px"/&gt;Dropdown link2&lt;/a&gt;&lt;/li&gt;
        &lt;li&gt;&lt;a href="#"&gt;&lt;img src="#" height="32px" width="32px"/&gt;Dropdown link3&lt;/a&gt;&lt;/li&gt;
        &lt;li&gt;&lt;a href="#"&gt;&lt;img src="#" height="32px" width="32px"/&gt;Dropdown link4&lt;/a&gt;&lt;/li&gt;
      &lt;/ul&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p><a href="http://jsfiddle.net/rainerpl/ZuMv5/5/" rel="nofollow">http://jsfiddle.net/rainerpl/ZuMv5/5/</a></p>
  
  <p>I'd like the blue hover on the big button to remain when clicked/active, tried :active, :focus via CSS and some jQuery workarounds but nothing works. I'd prefer a solution via CSS if possible.</p>
  
  <p>Also, is there any way to center the dropdown menu in relation to the big button above?</p>