* {
	margin: 0;
	padding: 0;
}

ul {
	list-style: none;
}

body {
	font-size: 13px;
	background-color: #333;
}

.nav {
	width: 700px;
	height: 42px;
	margin: 100px auto;
	background: #fff;
	border-radius: 10px;
	position: relative;
}

.nav li {
	width: 83px;
	height: 42px;
	text-align: center;
	line-height: 42px;
	float: left;
	cursor: pointer;
}
.nav li:hover {
	color: red;
	font-weight: bold;
}
ul {
	position: relative;
}

.nav span {
	position: absolute;
	top: 0;
	left: 0;
	width: 83px;
	height: 42px;
	background: url(../images/cloud.png) no-repeat;
}