nav a:last-child{
	border-bottom: 2px solid white;
}
.introduce{
	width: 760px;
	height: 660px;
	margin: 50px auto;
}
.introduce div{
	margin-bottom: 20px;
	color: white;
	text-indent: 2em;
}
.introduce img{
	width: 760px;
	height: 350px;
	margin-top: 20px;
}
.introduce ul{
	margin-top: 40px;
}
.introduce ul li{
	margin-top: 20px;
	color: white;
}
.introduce ul li span{
	display: inline-block;
}
.introduce ul li span:first-child{
	width: 360px;
	margin-right: 120px;
}