demo.css

body,html{
	padding: 0;
	margin: 0;
	font-family: Arial, Helvetica, sans-serif;
}

#wrapper {
	width: 100%;
	max-width: 960px;
	margin: auto;
}

.menu {
	background-color: #eee;
	width: 100%;
	height: 40px;
}

ul {
	margin: 0;
	padding: 0;
}
ul li {
	float: left;
	position: relative;
	margin-right: 5px;
}

ul li ul {
	display: none;
	position: absolute;
	left: 0;
}
ul li:hover ul{
	display: block;;
}

ul li ul ul li{
	margin-left: 10px;
}