.box {
    width: 100%;
    height: 700px;
    position: relative;
}


.box-img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    opacity: 0;/*透明度*/
    transition: all 1.5s;
}

.box-img:nth-child(1){
    opacity: 1;
}

.box-img img{
    width: 100%;
    height: 700px;
}

.box-left {
    position: absolute;
    width: 35px;
    height: 70px;
    background-color: #00000050;
    color: #ccc;
    top: 325px;
    border-radius: 0 5px 5px 0;
    text-align: center;
    line-height: 70px;
    font-size: 27px;
}

.box-left:hover {
    background-color: #00000050;
    color: #fff;
}

.box-right {
    position: absolute;
    width: 35px;
    height: 70px;
    background-color: #00000050;
    color: #ccc;
    top: 325px;
    border-radius: 5px 0 0 5px;
    text-align: center;
    line-height: 70px;
    font-size: 27px;
    right: 0;
}

.box-right:hover {
    background-color: #00000050;
    color: #fff;
}

.box-circle > ul {
    padding: 0;
    margin: 0;
    list-style: none;
}

.box-circle li {
    width: 14px;
    height: 14px;
    border-radius: 100%;
    background-color: #ccc;
    float: left;
    margin-right: 10px;
}

.box-circle li:hover {
    background-color: #fff;
}


.box-circle {
    position: absolute;
    bottom: 25px;
    right: 50%;
}