* {
	margin:0;
	padding:0;
}
ul li {
	list-style:none;
}
.box {
	width:120px;
	height:40px;
	margin:20px auto;
	border:1px solid #ddd;
	position:relative;
	overflow:hidden;
}
.box ul {
	position:absolute;
	text-align:center;
}
.box ul li {
	width:120px;
	height:40px;
	position:relative;
	font-size:14px;
	line-height:40px;
}
.box .angle {
	position:absolute;
	width:0px;
	height:0px;
	border-left:4px solid transparent;
	border-right:4px solid transparent;
}
.box .up {
	right:0;
	top:2px;
	border-bottom:4px solid #333;
}
.box .down {
	border-top:4px solid #333;
	bottom:0px;
	right:0;
}