.bg {
    width: 1440px;
    height: 500px;
    margin:0 auto;
    position: relative;
    overflow:hidden;}

.bgnav{
    width: 500%;
    display:flex;
    position: absolute;}
.bg .bgnav img{
   width: 1440px;
   height: 500px;}

.bgnav li{
    list-style: none;}

/* 左右按钮的添加 */
.right,
.left
{
    visibility: hidden; 
    position: absolute;
    width: 50px;
    height: 50px;
    top: 45%;
    font-size: 25px;
    border: none;
    border-radius: 50%;
    background: rgba(0, 0, 0, .1);
    color: #fff;
    z-index: 2;}

.bg .right{
    left: 96%;}

.bg .left{
    right: 96%;}

/* 小圆圈的添加 */
.circle{ 
    display: flex; 
    position: absolute;
    width: 120px;
    height: 40px;
    left: 92%;
    bottom: 0;
    margin-left: -70px;
    margin-bottom: 20px;
    border-radius: 10px;
    background: rgba(225, 255, 255, .2);}
.circle li{
 list-style: none;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: white;
    margin: auto;}