.nav_content{
    width:1000px;
    margin:0 auto;}
.nav_content ul{
    list-style:none;}
.nav_content ul a{
    color:#fff;
    font-size: 18px;
    font-weight:bold;}
.nav_content ul li{
    width:125px; 
    height:50px; 
    line-height:50px; 
    float:left; 
    text-align:center; 
    position:relative;}
.nav_content ul li ul{
    display:none;}
.nav_content ul li ul li{
    background:#176CC7;
    border-bottom: 1px dotted #6CA1DC;
    filter: alpha(opacity=70);
    -moz-opacity: 0.7;
    opacity: 0.7;}

.nav_content ul li ul li a{
    color:#fff;
    font-size: 16px;}

.nav_content ul li ul{
    color:#fff;}