/*背景_[猫之书_mzhis.com]*/
body::before {
    z-index: -1;
    content: "";
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.1;
    position: fixed;
    background: center/cover no-repeat;
    background-image: url(); 
}