<nav id="navclam">
   <ul>
     <li>
       <a href="http://big12sports.collegesports.com/">Big XII       </a>
       <ul>
         <li>
           <a href="http://www.baylor.edu/">Baylor           </a>
         </li>
         <li>
           <a href="http://www.iastate.edu/">Iowa State           </a>
         </li>
         <li>
           <a href="http://www.ku.edu/">Kansas           </a>
         </li>
         <li>
           <a href="http://www.ksu.edu/">Kansas State           </a>
         </li>
         <li>
           <a href="http://www.ou.edu/">Oklahoma           </a>
         </li>
         <li>
           <a href="http://www.okstate.edu/">Oklahoma State           </a>
         </li>
         <li>
           <a href="http://www.tcu.edu/">Texas Christian           </a>
         </li>
         <li>
           <a href="http://www.utexas.edu/">Texas           </a>
         </li>
         <li>
           <a href="http://www.ttu.edu/">Texas Tech           </a>
         </li>
         <li>
           <a href="http://www.wvu.edu/">West Virginia           </a>
         </li>       </ul>
     </li>
     <li>
       <a href="http://www.ivyleaguesports.com/">Ivy League       </a>
       <ul class="collapse">
         <li>
           <a href="http://www.brown.edu/">Brown           </a>
         </li>
         <li>
           <a href="http://www.columbia.edu/">Columbia           </a>
         </li>
         <li>
           <a href="http://www.cornell.edu/">Cornell           </a>
         </li>
         <li>
           <a href="http://www.dartmouth.edu/">Dartmouth           </a>
         </li>
         <li>
           <a href="http://www.harvard.edu/">Harvard           </a>
         </li>
         <li>
           <a href="http://www.upenn.edu/">Penn           </a>
         </li>
         <li>
           <a href="http://www.princeton.edu/">Princeton           </a>
         </li>
         <li>
           <a href="http://www.yale.edu/">Yale           </a>
         </li>       </ul>
     </li>
     <li>
       <a href="http://www.pac-12.com/">Pac 12       </a>
       <ul class="collapse">
         <li>
           <a href="http://www.arizona.edu/">Arizona           </a>
         </li>
         <li>
           <a href="http://www.asu.edu/">Arizona State           </a>
         </li>
         <li>
           <a href="http://www.berkeley.edu/">California           </a>
         </li>
         <li>
           <a href="http://www.cu.edu/">Colorado           </a>
         </li>
         <li>
           <a href="http://www.uoregon.edu/">Oregon           </a>
         </li>
         <li>
           <a href="http://www.oregonstate.edu/">Oregon State           </a>
         </li>
         <li>
           <a href="http://www.stanford.edu/">Stanford           </a>
         </li>
         <li>
           <a href="http://www.ucla.edu/">UCLA           </a>
         </li>
         <li>
           <a href="http://www.usc.edu/">USC           </a>
         </li>
         <li>
           <a href="http://www.utah.edu/">Utah           </a>
         </li>
         <li>
           <a href="http://www.washington.edu/">Washington           </a>
         </li>
         <li>
           <a href="http://www.wsu.edu/">Washington State           </a>
         </li>       </ul>
     </li>   </ul> </nav> 

In head element:

<link rel="stylesheet" href="example3.css"/>

In example3.css

#navclam {
    font-family: Arial, Verdana, Helvetica, sans-serif;
    font-weight: bold;
    font-size: 1.2em;
    width: 10em;
    border-right: 1px solid #333;
    margin-bottom: 1em;
    background-color: #ddd;
    color: #900;
  }
  #navclam ul {
    list-style: none;
    margin: 0;
    padding: 0;
  }
  #navclam ul li {
    margin: 0;
    border-top: 1px none #333;
  }
  #navclam ul li a {
    display: block;
    background-color: #ccc;
    border-top: 1px none #333;
    border-right: 1px solid #333;
    border-bottom: thin dotted #333;
    border-left: 5px solid #333;
    text-decoration: none;
    padding: 5px 2px 5px 0.5em;
  }
  #navclam a:link {
    color: #900;
  }
  #navclam a:visited {
    color: #900;
  }
  #navclam a:hover {
    color: #fff;
    background-color: #900;
    border-top: 1px outset #333;
    border-right: 1px outset #333;
    border-bottom: 1px outset #333;
    border-left: 5px outset #333;
  }
  #navclam a:active {
    color: #fff;
    background-color: #900;
    border-top: 1px inset #333;
    border-right: 1px inset #333;
    border-bottom: 1px inset #333;
    border-left: 5px inset #333;
  }
  #navclam ul ul {
    list-style: none;
  }
  #navclam ul ul a {
    padding-left: 1.5em;
    font-size: 90%;
    font-weight: normal;
  }
  #navclam ul.collapse {
    display: none;
  }