.pagetop {
 display: none;
 position: fixed;
 bottom: 20px;
 right: 20px;
 border-radius:5px;
 z-index:999;
}
.pagetop a {
 display: block;
 width: 50px;
 height: 50px;
 background-color: #1f80bf;
 text-align: center;
 color: #fff;
 font-size: 24px;
 text-decoration: none;
 line-height: 45px;
 border-radius:5px;
}