.logo img{max-width: 200px;}
.nav1 li{
position:relative;}
.nav1 li span{
    background: url(images/arr.png) 100% no-repeat;
    width: 18px;
    height: 32px;
    position: absolute;
    z-index: 999;
    top: 19px;
    transform: translateY(-50%);
    transition: all .3s;}

.nav1 li.on span{
    transform: rotate(90deg);}

.nav1 li.on .nav2{display:block;}
.dd{}