CSS multi levels menu.txt

<style>
/* Some stylesheet reset */
.nav, .nav ul {
	margin: 0;
	padding: 0;
	list-style: none;
	line-height: 1;
}

/* The main container */
.nav {
	/* Layout and positioning */
	display: block;
	position: relative;
	height: 34px;
	width: 750px; /* CHANGE this if you want another width or remove it if you want the width of the container */
	border-radius: 3px;
	border: 1px solid #c1c1c1;

	/* Background and effects */
	background: #eaeaea; /* Background for IE9 and older browsers */
	background: -webkit-linear-gradient(bottom, #e1e1e1, #f4f4f4); /* Background for Chrome Safari */
	background: -moz-linear-gradient(bottom, #e1e1e1, #f4f4f4); /* Background for Firefox */
	background: -o-linear-gradient(bottom, #e1e1e1, #f4f4f4); /* Background for Opera */
	background: -ms-linear-gradient(bottom, #e1e1e1, #f4f4f4); /* Background for Internet Explorer 10 */
	box-shadow: inset 0 1px 0 #fff;
}

.nav>li {
	display: block;
	position: relative;
	float: left;
	margin: 0;
	padding: 0 1px 0 0;
}

/* The main navigation links */
.nav>li>a {
	/* Layout */
	display: block;
	padding: 11px 20px;

	/* Typography */
	font-family: Helvetica, Arial, sans-serif;
	font-size: 12px;
	font-weight: normal;
	text-decoration: none;
	color: #9a9a9a;
	text-shadow: 0 1px 0 #fff;

	/* Effects */
	-webkit-transition: all .3s;
	-moz-transition: all .3s;
	-ms-transition: all .3s;
	-o-transition: all .3s;
	transition: all .3s;
}

/* The hover state of the navigation links */
.nav>li>a:hover, .nav>li:hover>a {
	background: #fff;
	background: rgba(255, 255, 255, .6);
	color: #999;
}

.nav>li:first-child>a {
	border-top-left-radius: 3px;
	border-bottom-left-radius: 3px;
}

.nav>.dropdown>a {
	padding-right: 26px;
}

/* The arrow indicating a dropdown menu */
.nav>.dropdown>a::after {
	 content: "";
	 position: absolute;
	 top: 14px;
	 right: 11px;
	 width: 4px;
	 height: 4px;
	 border-bottom: 1px solid #9a9a9a;
	 border-right: 1px solid #9a9a9a;
	 -webkit-transform: rotate(45deg);
	 -ms-transform: rotate(45deg);
	 -moz-transform: rotate(45deg);
	 -o-transform: rotate(45deg);
	}

/* Changing the color of the arrow on hover */
.nav>.dropdown>a:hover::after, .nav>.dropdown:hover>a::after {
	border-color: #999;
}

.nav ul {
	position: relative;
	position: absolute;
	left: -9999px;
	display: block;
	box-shadow: 0 1px 2px rgba(0, 0, 0, .1);
}

/* Level 1 submenus */
.nav>li>ul {
	padding-top: 0px;
	z-index: 99;
	border-top: 1px solid #c9c9c9;
	top: 34px;
}

/* Making the level 1 submenu to appear on hover */
.nav>li:hover>ul {
	left: -1px;
}

/* Level 2+ submenus */
.nav ul ul {
	left: -9999px;
	top: 0px;
	z-index: 999;
}

/* Making the level 2+ submenu to appear on hover */
.nav ul>li:hover>ul {
	left: 120px;
	top: -1px;
}

/* The submenu link containers */
.nav ul li {
	position: relative;
	display: block;
	border-left: 1px solid #c1c1c1;
	border-right: 1px solid #c1c1c1;

	/* Creating the slide effect. The list elements which contain the links have 0 height. On hover, they will expand */
	height: 0px;
	-webkit-transition: height .3s;
	-moz-transition: height .3s;
	-o-transition: height .3s;
	-ms-transition: height .3s;
}

/* Expanding the list elements which contain the links */
.nav li:hover>ul>li {
	height: 25px;
}

.nav ul li:hover>ul>li:first-child {
	height: 26px;
}

/* The links of the submenus */
.nav ul li a {
	/* Layout */
	display: block;
	width: 90px;
	padding: 6px 10px 6px 20px;
	border-bottom: 1px solid #e1e1e1;

	/* Typography */
	font-size: 12px;
	color: #a6a6a6;
	font-family: Helvetica, Arial, sans-serif;
	text-decoration: none;
	
	/* Background  effects */
	background: #fff;
	-webkit-transition: background .3s;
	-moz-transition: background .3s;
	-ms-transition: background .3s;
	-o-transition: background .3s;
	transition: background .3s;
}

/* The hover state of the links */
.nav ul li>a:hover, .nav ul li:hover>a {
	background: #e9e9e9;
	color: #a1a1a1;
}

.nav ul ul>li:first-child>a {
	border-top: 1px solid #c1c1c1;
}

.nav ul>li:last-child>a {
	border-bottom: 1px solid #c1c1c1;
}


/* The arrow indicating a level 2+ submenu */
.nav ul>.dropdown>a::after {
	content: "";
	 position: absolute;
	 top: 10px;
	 right: 8px;
	 width: 4px;
	 height: 4px;
	 border-bottom: 1px solid #a6a6a6;
	 border-right: 1px solid #a6a6a6;
	 -webkit-transform: rotate(-45deg);
	 -ms-transform: rotate(-45deg);
	 -moz-transform: rotate(-45deg);
	 -o-transform: rotate(-45deg);
}

.nav ul>.dropdown:hover>a::after, .nav ul>.dropdown>a:hover::after {
	border-color: #a1a1a1;
}
</style>
<ul class="nav">
	<li><a href="#">Home</a></li>
	<li class="dropdown"><a href="#">Link 2</a>
	<ul>
		<li><a href="#">Level 1</a></li>
		<li><a href="#">Level 1</a></li>
		<li class="dropdown"><a href="#">Level 1</a>
		<ul>
			<li><a href="#">Level 2</a></li>
			<li><a href="#">Level 2</a></li>
			<li><a href="#">Level 2</a></li>
			<li class="dropdown"><a href="#">Level 2</a>
			<ul>
				<li><a href="#">Level 3</a></li>
				<li><a href="#">Level 3</a></li>
				<li><a href="#">Level 3</a></li>
				<li><a href="#">Level 3</a></li>
				<li><a href="#">Level 3</a></li>
			</ul>
			</li>
			<li><a href="#">Level 2</a></li>
		</ul>
		</li>
		<li><a href="#">Level 1</a></li>
		<li><a href="#">Level 1</a></li>
	</ul>
	</li>
	<li><a href="#">Link 2</a></li>
	<li><a href="#">Link 3</a></li>
	<li><a href="#">Link 4</a></li>
	<li><a href="#">Link 5</a></li>
</ul>