only CSS
using CSS transitions
by isuru_nan
HTML
<div id="navbar">
<ul id="main-menu">
<li><a href="#">Home</a></li>
<li><a href="#">About US</a></li>
<li><a href="#">Publications</a>
<ul>
<li><a href="#">Sub menu item 1</a></li>
<li><a href="#">Sub menu item 2</a></li>
</ul>
</li>
<li><a href="#">Members</a>
<ul>
<li><a href="#">Sub menu item 3</a></li>
<li><a href="#">Sub menu item 4</a></li>
</ul>
</li>
<li><a href="#">Events</a>
<ul>
<li><a href="#">Sub menu item 5</a></li>
<li><a href="#">Sub menu item 6</a></li>
</ul>
</li>
<li><a href="#">Contact Us</a></li>
</ul>
</div>
CSS
#navbar {
width:550px;
height:30px;
position:relative;
float:right;
right:-7px;
top:30px;
}
#main-menu {
width:100%;
float:right;
list-style:none;
}
#main-menu li {
float:left;
}
#main-menu li a {
display:block;
text-decoration:none;
color:#000;
background-color:#FC0;
padding:8px;
margin-right:10px;
-webkit-transition: background-color 0.3s ease;
-moz-transition: background-color 0.3s ease;
}
#main-menu li a:hover {
background-color:#C60;
}
#main-menu li ul {
display:none;
z-index:999;
}
#main-menu li:hover ul {
display:block;
position:absolute;
}
#main-menu li li {
display:block;
float:none;
}