.dropdown {
  position: relative;
  display: inline-block;
}
.dropdown-content {
  display: none;
  position: absolute;
  background: rgba(0, 0, 0, 0.40);
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  padding: 12px 16px;
  color: white;
}
.dropdown:hover .dropdown-content {
  display: block;
}
.buttonsub{
  background: rgba(0, 0, 0, 0) none repeat scroll 0 0;
  border: 1px solid #ccc;
  color: #444;
  font-size: 16px;
  font-weight: 700;
  margin-top: 8px;
  padding: 12px 30px;
  text-transform: uppercase;
  transition: all 0.3s ease 0s;
  border-radius: 30px;
}
/*wrap的轮播图和切换按钮样式*/
.wrap{height: 170px;width: 500px;margin: 0px auto; overflow: hidden;position: relative;}
.wrap ul{position: absolute;}
.wrap ul li{height: 170px;}
.wrap ol{position: absolute;right: 10px;bottom: 10px;}
.wrap ol li{height: 20px;width: 20px;  background-color:#fff;border: 1px solid #eee;border-radius: 100% ;margin-left: 10px;float:left; line-height: 20px; text-align: center;}
.wrap ol li.active{background-color: #330099; color: #fff; border: 2px solid #aaa;}