/* 2.背景图片设置 */
body {
background-color: #efefef;
//background-image: url(https://images.cnblogs.com/cnblogs_com/2979100039-qq-
// con/1650464/t_2002190550137.jpg?a=1582542727623);
background-image: url(https://images.cnblogs.com/cnblogs_com/blogs/847444/galleries/2462558/t_250620172943_v-93e14d55b5bf059a63f14d91a14894512_r.jpg);
background-repeat: no-repeat;
background-attachment: fixed;
background-position: center 0;
background-size: cover;
}