title: How to make content div not overlap header?
body: <p>i got an html structure as below, </p>
  
  <pre><code>&lt;div id="page-wrap"&gt;
      &lt;header&gt;
          &lt;div id="logo"&gt;
          &lt;/div&gt;
          &lt;nav&gt;
              &lt;ul&gt;
                  &lt;li&gt;&lt;a href=""&gt;text 1&lt;/a&gt;&lt;li&gt;
                  &lt;li&gt;&lt;a href=""&gt;text 2&lt;/a&gt;&lt;/li&gt;
                  &lt;li&gt;&lt;a href=""&gt;text 3&lt;/a&gt;&lt;/li&gt;
              &lt;/ul&gt;
          &lt;/nav&gt;
      &lt;/heder&gt;
  
      &lt;div id="main-content"&gt;
          &lt;h1&gt;Some Heading&lt;/h1&gt;
          &lt;p&gt;Some Text&lt;/p&gt;
          &lt;div&gt;A div&lt;/div&gt;
      &lt;/div&gt; &lt;!-- end of main-content --&gt;
  &lt;/div&gt; &lt;!-- end of page-wrap --&gt;
  </code></pre>
  
  <p>with css</p>
  
  <pre><code>#page-wrap {
  max-width:850px;
  top:0;
  bottom:0;
  height:100%;
  margin: 0 auto;
  } 
  
  header {
  padding: 80px 0px 0px 0px ;
  position: relative;
  }
  
  #logo {
  position: absolute;
  left:0;
  width:123px;
  height:122px;
  background:transparent url(../images/logo.png) no-repeat;
  }
  
  header nav {
  position: absolute;
  right:0;
  }
  
  header nav ul {
  
  }
  
  header nav ul li {
  display:inline;
  list-style: none;
  }
  </code></pre>
  
  <p>as above.. the main-content div overlaps the header >.&lt; please suggest propper css for getting main-content have an 80px distance from bottom of the header.. (there is a logo with 122px height on the header)</p>