body {
    background-repeat: no-repeat;  
    background: rgba(12, 100, 129, 0) url('https://images.cnblogs.com/cnblogs_com/chaiyinlei/1655941/o_2002261642360eebb50f7c7060f9edccfb10aa046da8.jpg') fixed;
    background-position: 100%  50%; 
    background-size: 100% 100%;

}