#header(display:none;)/*屏蔽默认导航头*/

#showtop ui{
    margin:0;
    padding:0;
    list-style-type:none;
    background-color: #333;
    overflow: hidden;
}
#show li{
    float:left;
}

#show li a, .dropbtn{
    display: inline-block;//设置块
    color: white;
    text-align: none;
    padding:14px 16px;
}

#showtop li a:hover, .dropdown:hover .dropbtn{
    background-color: blue;
}

#showtop .dropdown{
    display: inline-block;
}
#shwtop .dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
}
#shwtop .dropdown-content a {
    display: block;
    color: black;
    padding: 8px 10px;
    text-decoration:none;
}
#shwtop .dropdown-content a:hover {
    background-color: #a1a1a1;
}
#shwtop .dropdown:hover .dropdown-content{
    display: block;
}