.header {
    width: 1000px;
    height: 45px;
    position: relative;
    margin: 0 auto;
    z-index: 1000;
}




.nv li{
    width:auto;
    height:17px;
    float:left;
    margin: 0 60px 0 0;}
.nv .last{
    margin:0;}
.nv a{
    font-size:18px;
    color:black;}
.nv .a{
    color:#ff6600;}
.nv a:hover{
    color:#ff6600;}