.wraper{ width:1000px; padding-top:100px; margin:0 auto}
.nav{position:relative;
	width:450px;
	height:40px;
	background:#ffffff;
	overflow:hidden}
.nav-item{ position:relative; float:left; width:90px; height:40px; line-height:40px; text-align:center; font-size:14px; z-index:1}
.nav-item a{ display:block; height:40px; color:#000000; }
.nav-item a:hover{ color:#000000}
.move-bg{ display:none;position:absolute;left:0;top:0; width:90px; height:40px; background-image:url(../images/1btn90.png); z-index:0}