CSS3制作的二级旋转菜单，鼠标移入时二级菜单透明度变化便随着Y轴方向的选择，并且带有层次感。

Html

<ul id="MenuUl">
		<li class="MenuItem"><a>菜单1</a>
			<div id="MenuMark"></div>
			<ul id="MenuItemChild">
				<li class="MenuItemChildItem"><a>菜单1-1</a></li>
				<li class="MenuItemChildItem"><a>菜单1-2</a></li>
				<li class="MenuItemChildItem"><a>菜单1-3</a></li>
				<li class="MenuItemChildItem"><a>菜单1-4</a></li>
				<li class="MenuItemChildItem"><a>菜单1-5</a></li>
				<li class="MenuItemChildItem"><a>菜单1-6</a></li>
			</ul>
		</li>
		<li class="MenuItem"><a>菜单2</a>
			<div id="MenuMark"></div>
			<ul id="MenuItemChild">
				<li class="MenuItemChildItem"><a>菜单2-1</a></li>
				<li class="MenuItemChildItem"><a>菜单2-2</a></li>
				<li class="MenuItemChildItem"><a>菜单2-3</a></li>
				<li class="MenuItemChildItem"><a>菜单2-4</a></li>
				<li class="MenuItemChildItem"><a>菜单2-5</a></li>
				<li class="MenuItemChildItem"><a>菜单2-6</a></li>
			</ul>
		</li>
		<li class="MenuItem"><a>菜单3</a>
			<div id="MenuMark"></div>
			<ul id="MenuItemChild">
				<li class="MenuItemChildItem"><a>菜单3-1</a></li>
				<li class="MenuItemChildItem"><a>菜单3-2</a></li>
				<li class="MenuItemChildItem"><a>菜单3-3</a></li>
				<li class="MenuItemChildItem"><a>菜单3-4</a></li>
				<li class="MenuItemChildItem"><a>菜单3-5</a></li>
				<li class="MenuItemChildItem"><a>菜单3-6</a></li>
			</ul>
		</li>
		<li class="MenuItem"><a>菜单4</a>
			<div id="MenuMark"></div>
			<ul id="MenuItemChild">
				<li class="MenuItemChildItem"><a>菜单4-1</a></li>
				<li class="MenuItemChildItem"><a>菜单4-2</a></li>
				<li class="MenuItemChildItem"><a>菜单4-3</a></li>
				<li class="MenuItemChildItem"><a>菜单4-4</a></li>
				<li class="MenuItemChildItem"><a>菜单4-5</a></li>
				<li class="MenuItemChildItem"><a>菜单4-6</a></li>
			</ul>
		</li>
		<li class="MenuItem"><a>菜单5</a>
			<div id="MenuMark"></div>
			<ul id="MenuItemChild">
				<li class="MenuItemChildItem"><a>菜单5-1</a></li>
				<li class="MenuItemChildItem"><a>菜单5-2</a></li>
				<li class="MenuItemChildItem"><a>菜单5-3</a></li>
				<li class="MenuItemChildItem"><a>菜单5-4</a></li>
				<li class="MenuItemChildItem"><a>菜单5-5</a></li>
				<li class="MenuItemChildItem"><a>菜单5-6</a></li>
			</ul>
		</li>
	</ul>

CSS

a, .MenuItemChildItem>a {
	float: left;
	color: #fff;
	padding: 10px 0px 10px 0px;
	text-align: center;
	font: 15px "微软雅黑", Arial, Helvetica, sans-serif;
	cursor: pointer;
	width: 120px;
}
.MenuItem>a:hover {
	background-color: #252525;
}
.MenuItem:first-child>a {
	-webkit-border-radius: 5px 0 0 0;
	-moz-border-radius: 5px 0 0 0;
	border-radius: 5px 0 0 0;
}
.MenuItem:hover #MenuMark {
	width: 100%;
}
#MenuItemChild {
	margin: 0;
	visibility:hidden;
	padding: 0;
	width: 100%;
	float: left;
}
#MenuItemChild>li>a {
	background-color: #333;
	
}
.MenuItemChildItem {
	list-style: none;
	color: #fff;
	-webkit-perspective: 300px;
	-moz-perspective: 300px;
	-ms-perspective: 300px;
	-o-perspective: 300px;

	perspective: 300px;
}
.MenuItemChildItem>a {
	border-bottom: 1px solid #222222;
	border-top: 1px solid #555555;
	-webkit-transform: rotateY(90deg);
	transition-duration: 0.5s;
	-webkit-perspective: 400px;
	-moz-perspective: 400px;
	-ms-perspective: 400px;
	-o-perspective: 400px;
	perspective: 400px;
	opacity:0;
}
.MenuItem:hover #MenuItemChild{
	visibility:visible;
}
.MenuItemChildItem>a:hover {
	background-color: #252525 !important;
}
.MenuItem:hover #MenuItemChild>li:nth-child(1)>a {
	opacity: 1;
	
	-webkit-transform: rotateY(0deg);
}
.MenuItem:hover #MenuItemChild>li:nth-child(2)>a {
	opacity: 1;
	transition-delay: 0.2s;
	-webkit-transform: rotateY(0deg);
}
.MenuItem:hover #MenuItemChild>li:nth-child(3)>a {
	opacity: 1;
	transition-delay: 0.4s;
	-webkit-transform: rotateY(0deg);
}
.MenuItem:hover #MenuItemChild>li:nth-child(4)>a {
	opacity: 1;
	transition-delay: 0.5s;
	-webkit-transform: rotateY(0deg);
}
.MenuItem:hover #MenuItemChild>li:nth-child(5)>a {
	opacity: 1;
	transition-delay: 0.6s;
	-webkit-transform: rotateY(0deg);
}
.MenuItem:hover #MenuItemChild>li:nth-child(6)>a {
	opacity: 1;
	transition-delay: 0.8s;
	-webkit-transform: rotateY(0deg);
}