div {

            width: 600px;

            height: 200px;

            /* 背景渐变必须添加浏览器私有前缀 */

            /* background: -webkit-linear-gradient(left, red, blue); */

            /* background: -webkit-linear-gradient(red, blue); */

            background: -webkit-linear-gradient(top left, red, blue);

        }