Another Simple CSS3 Dropdown Menu

<style>
/* foulscode.blogspot.com */
body {
  font-family: 'Lucida Grande', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  margin: 0;
  font-size: 13px;
  text-align: center;
  background: #2196F3;
}

ul {
  text-align: left;
  display: inline;
  margin: 0;
  padding: 15px 4px 17px 0;
  list-style: none;
  box-shadow: 0 2px 5px 0 rgba(0,0,0,0.16),0 2px 10px 0 rgba(0,0,0,0.12);
}
ul li {
  font: bold 12px/18px sans-serif;
  display: inline-block;
  margin-right: -4px;
  position: relative;
  padding: 15px 20px;
  background: #00BCD4;
  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;
  color: #fff;
}
ul li:hover {
  background: #4DD0E1;
  color: #fff;
}
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;
  box-shadow: 0 2px 5px 0 rgba(0,0,0,0.16),0 2px 10px 0 rgba(0,0,0,0.12);
}
ul li ul li {
  background: #00ACC1;
  display: block;
  color: #fff;
}
ul li ul li:hover { background: #4DD0E1;}
ul li:hover ul {
  display: block;
  opacity: 1;
  visibility: visible;
}
.home {
  border-top-left-radius: 3px;
  border-bottom-left-radius: 3px;
}
.contact {
  border-top-right-radius: 3px;
  border-bottom-right-radius: 3px;
}
.ill {
  border-bottom-right-radius: 3px;
  border-bottom-left-radius: 3px;
}
menu {
  padding-top: 200px;
}
/* foulscode.blogspot.gr */
</style>
<menu>
<ul><li class='home'>Home</li>
  <li>About</li>
  <li>
    Portfolio
    <ul>
      <li>Web Design</li>
      <li>Web Development</li>
      <li class='ill'>Illustrations</li>
    </ul>
  </li>
  <li>Blog</li>
  <li class='contact'>Contact</li>
</ul>
</menu>