.AnMenu li {
background-color: #03f;
-webkit-transition: all 0.3s ease-in-out 0s;
-moz-transition: all 0.3s ease-in-out 0s;
-o-transition: all 0.3s ease-in-out 0s;
-ms-transition: all 0.3s ease-in-out 0s;
transition: all 0.3s ease-in-out 0s;
height:3px;
font-size:20px;
padding:0px;
margin:0;
list-style:none;
float:left;
}
.AnMenu li a {
line-height:50px;
padding:0px 21px;
color:#000;
}
.AnMenu li a:hover {
color:#eee;
}
.AnMenu li:hover {
background-color: #03f;
height:55px;
}<ul class="AnMenu">
<li><a href="#">Home</a></li>
<li><a href="#">Services</a></li>
<li><a href="#">Gallery</a></li>
<li><a href="#">About</a></li>
</ul>http://www.flashuser.net/tutorials/css3-animation-menus/
