body {
    background-repeat: no-repeat;  
    background: rgba(12, 100, 129, 0) url('https://images.cnblogs.com/cnblogs_com/blogs/753011/galleries/2161460/o_220515144446_anime.jpg') fixed;
    background-position: 100%  50%; 
    background-size: 100% 100%;
}
#content_canvas {
  position: fixed;
  right: 0px;
  bottom: 0px;
  min-width: 100%;
  min-height: 100%;
  height: auto;
  width: auto;
  z-index: -1;
}