.banner {
            width: 1200px;
            height: 400px;
            border: 0px;
            margin: 0px auto;
            overflow: hidden;
            display: flex;
            position: relative;
        }
        
        .banner img {
            width: 100%;
            height: 100%;
        }
        /*
        设置小圆点的容器，利用flex布局使其居中
        */
        
        .banner .points {
            position: absolute;
            color: #fff;
            width: 100%;
            bottom: 10px;
            height: 30px;
            display: flex;
            justify-content: center;
            align-items: center;
        }
        /* 设置每个小圆点的样式 */
        
        .banner .point {
            background-color: skyblue;
            width: 10px;
            height: 10px;
            border-radius: 50%;
            margin: 5px;
            cursor: pointer;
        }
        
        .points .active {
            background-color: #f40;
        }
        /* 制作左右箭头 */
        
        .banner .left-btn,
        .banner .right-btn {
            z-index: 999;
            color: #fff;
            font-weight: 900;
            position: absolute;
            background-color: rgba(0, 0, 0, .2);
            height: 20px;
            width: 20px;
            display: flex;
            justify-content: center;
            align-items: center;
            cursor: pointer;
            margin-top: 190px;
        }
        
        .banner .left-btn {
            margin-left: -20px;
        }
        
        .banner .right-btn {
            margin-right: 50px;
            justify-content: center;
        }