* 
        

        
        #container {
            position: absolute;
            
            width: 800px;
            height: 400px;
           
            overflow: hidden;
        }
        
        #list {
            position: absolute;
            z-index: 1;
            /*几个图加起来的宽度*/
            width: 4000px;
            height: 400px;
        }
        
        #list img {
            
            float: left;
            width: 800px;
            height: 400px;
        }
        
        #buttons {
            position: absolute;
            left: 250px;
            bottom: 20px;
            z-index: 2;
            height: 10px;
        }
        
        #buttons span {
            float: left;
            margin-right: 5px;
            width: 10px;
            height: 10px;
            border: 1px solid #fff;
            border-radius: 50%;
            background: #333;
            cursor: pointer;
        }
        
        #buttons .on {
            background: #A3814F;
        }
        
        .arrow {
            position: absolute;
            top: 180px;
            z-index: 2;
            display: none;
            width: 40px;
            height: 40px;
            font-size: 36px;
            font-weight: bold;
            line-height: 39px;
            text-align: center;
            color: #fff;
            background-color: RGBA(0, 0, 0, .3);
            cursor: pointer;
        }
        
        .arrow:hover {
            background-color: RGBA(0, 0, 0, .7);
        }
        
        #container:hover .arrow {
            display: block;
        }
        
        #prev {
            left: 20px;
        }
        
        #next {
            right: 20px;
        }