响应式导航条，窄屏时没有弹出li的值

<nav class="navbar navbar-default navbar-fixed-top" role="navigation">
     <div class="container">
         <div class="navbar-header">
              <button class="navbar-toggle" type="button" data-toggle="collapse" data-target=".navCollapse">
                  <span class="sr-only">Toggle Navigation</span>             
                <span class="icon-bar"></span>
    <span class="icon-bar"></span>
                <span class="icon-bar"></span>
             </button>
               
            </div>
          
            <div class="navCollapse collapse navbar-collapse">
             <ul class="nav navbar-nav navbar-right">
                 <li>Canteens</li>
                    <li>Meals</li>
                    <li>Foods</li>
                    <li>Contact</li>
                </ul>
            </div>
           
        </div>
   </nav>