<ul><li>Home</li>
  <li>About</li>
  <li>
  Portfolio
  <ul>
  <li>Web Design</li>
  <li>Web Development</li>
  <li>Illustrations</li>
  </ul>
  </li>
  <li>Blog</li>
  <li>Contact</li>
</ul>

body {
  font-family: 'Lucida Grande', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  padding: 20px 50px 150px;
  font-size: 13px;
  text-align: center;
  background: #96d6df;
}

ul {
  text-align: left;
  display: inline;
  margin: 0;
  padding: 15px 4px 17px 0;
  list-style: none;
  -webkit-box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
  -moz-box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
}
ul li {
  font: bold 12px/18px sans-serif;
  display: inline-block;
  margin-right: -4px;
  position: relative;
  padding: 15px 20px;
  background: #fff;
  cursor: pointer;
  -webkit-transition: all 0.2s;
  -moz-transition: all 0.2s;
  -ms-transition: all 0.2s;
  -o-transition: all 0.2s;
  transition: all 0.2s;
}
ul li:hover {
  background: #f1f1f1;
  color: #333;
}
ul li ul {
  padding: 0;
  position: absolute;
  top: 48px;
  left: 0;
  width: 150px;
  -webkit-box-shadow: none;
  -moz-box-shadow: none;
  box-shadow: none;
  display: none;
  opacity: 0;
  visibility: hidden;
  -webkit-transiton: opacity 0.2s;
  -moz-transition: opacity 0.2s;
  -ms-transition: opacity 0.2s;
  -o-transition: opacity 0.2s;
  -transition: opacity 0.2s;
}
ul li ul li {  
  background: #f1f1f1;  
  display: block;  
  color: #333;
}
ul li ul li:hover { background: #fff; }
ul li:hover ul {
  display: block;
  opacity: 1;
  visibility: visible;
}