.head_div
{
    width:100%;
    font-size:18px;
    height:45x;
    background-color:#0082d8;
    overflow:hidden;   
    position:fixed;
    top:0;
    left:0;
    color:#ffffff;
}

.head_img
{
    width:50px;
    height:35px;
    float:left;    
    background-color:#0082d8;
    margin:5px;
}

.head_title
{
    width:200px;
    float:left;
    font-size:22px;
    line-height:45px;
    color:#ffffff;
    text-align:left;
}


.head_menu
{
    float:left;
    line-height:45px;
    font-weight:bold;
}

.head_tool
{
    float:right;
    line-height:45px;
    font-weight:bold;
    margin-right:50px;
}

ul{
    list-style: none;    
}

.nav>li{
    float: left;
    margin-top:-5px;
}

ul a{
    display: block;
    text-decoration: none;
    width: 110px;
    height: 28px;
    text-align: center;
    line-height: 1;
    color: #ffffff;
    background-color: #0082d8;
    
}

.drop-down{
    position: relative;    
}

.drop-down-content{
    padding: 0;
    display: none;
    position: fixed;
    z-index:10;
}

.drop-down-content li a
{
    display: block;
    text-decoration: none;
    width: 150px;
    height: 40px;
    font-size:18px;
    text-align: left;
    text-indent:1em;
    line-height:40px;
    color: #0082d8;
    background-color: #efefef;
    border:1px solid #efefef;
}

.drop-down-content li:hover a{
    background-color:#b3c7d4;
    color:#ffffff;
}

.nav .drop-down:hover .drop-down-content{
    display: block;
}