.head_nav{background: #3f81fb;/* margin-bottom: 20px; */}
.head_nav .head_menu .nav .menu .width{height: 160px;width: 110px;}
.head_nav .head_menu .nav{float: left;position: relative;}
.head_nav .head_menu .nav li a{font-size: 18px;color: #fff;line-height: 50px;display: block;}
.head_nav .head_menu .nav li a.on{font-weight: bold;}
.head_nav .head_menu .nav li:hover{font-weight: bold;}
.head_nav .head_menu .nav li{float: left;margin-right: 38px;width: 110px;text-align: center;}
.head_nav .head_menu .nav li .menu{position: absolute;width: 110px;top: 50px;height:0;overflow: hidden;transition: 0.5s; -moz-transition: 0.5s; -webkit-transition: 0.5s;z-index: 999;background: #f5f5f5;}
.head_nav .head_menu .nav li:hover .menu{height: 160px;}
.head_nav .head_menu .nav li .menu a{display: block;line-height: 30px;text-align: center;color: #424242;font-size: 14px;}