title: Nav bar comes on top of header
body: <p>I have the following CSS code, and my problem is that my 
  nav bar comes on top of my header block. How can I move
  the nav bar straight down from the header?</p>
  
  <pre><code>header {                                                                                
      background: black;                                                                  
      height: 60px;                                                                       
      left: 0;                                                                            
      margin: 0;                                                                          
      padding: 0;                                                                         
      position: absolute;                                                                 
      width: 100%;                                                                        
  }                                                                                       
  
  header img {                                                                            
      float: left;                                                                        
      margin-right: 10px;                                                                 
      position: relative;                                                                 
  }                                                                                       
  
  header h1 {                                                                             
      color: white;                                                                       
      font: 26px Helvetica, Arial, sans-serif;                                            
      line-height: 60px;                                                                  
      margin: 0;                                                                          
      vertical-align: middle;                                                             
  }                                                                                       
  
  nav {                                                                                   
      background: black;                                                                  
      margin: 0;                                                                          
      padding: 0;                                                                         
      position: absolute;                                                                 
      width: 100%;                                                                        
  }
  </code></pre>