title: Cancel some CSS Style
body: <p>For one project, I've to use a defined stylesheet. I cannot edit it, I've to take it as it comes.</p>
  
  <p>But, there is some styles which aren't adequate for this website(e.g. margin).</p>
  
  <p>I've too create my own CSS file which override some of those properties.</p>
  
  <p>One example, if I've this:</p>
  
  <pre><code>&lt;div id="main-content" class="container"&gt;My test text&lt;/div&gt;
  </code></pre>
  
  <p>And the following css instruction in a css file:</p>
  
  <pre><code>div.container{margin:5px}
  div#main-content{margin-left:235px; ...}
  </code></pre>
  
  <p>I would like in MY css to define that the div#main-content hasn't this margin but it's default value.</p>
  
  <p>How could I do it? I don't want to do a <code>margin-left:0px</code> because if I've a global style(saying that all <code>div.container</code> should have a 5px margin, I would like it applies to my previous div. And thoses data could change.</p>