.scrollBtn {
    position: fixed;
    right: 15px;
    bottom: 45px;
    width: 54px
}

.scrollBtn a {
    display: inline-block;
    width: 54px;
    -webkit-transition: opacity .5s ease;
    transition: opacity .5s ease;
    text-align: center;
    opacity: .6;
    color: #fff;
    background: url(https://images2015.cnblogs.com/blog/459873/201601/459873-20160127210900473-1080897398.png) no-repeat;
    filter: alpha(opacity=60)
}

.scrollBtn li {
    float: left;
    margin-bottom: 5px
}

.scrollBtn a:hover {
    opacity: 1;
    filter: alpha(opacity=100)
}
.scrollBtn a, .scrollBtn li {
    overflow: hidden;
    height: 54px
}
.portrait {
    display: block;
    position: absolute;
    left: 0;
    top: 0;
    width: 100px;
    height: 100px;
    overflow: hidden;
    background-image: url("你的图片地址");
    background-size: 100% 100%;
    border-radius: 50%;
    background-repeat: no-repeat;
    overflow: hidden;
    transform-origin: center center;
    -webkit-transition: all 0.5s;
    -moz-transition: all 0.5s;
    -ms-transition: all 0.5s;
    -o-transition: all 0.5s;
    transition: all 0.5s;
}