css-背景图置于背景色的下方
background-image: linear-gradient(to top, rgba(25, 26, 50, 0.6), rgba(25, 26, 50, 0.6)),
url(../../../../assets/img/dark/num_back2.png);
background-image: linear-gradient(to top, rgba(25, 26, 50, 0.6), rgba(25, 26, 50, 0.6)),
url(../../../../assets/img/dark/num_back2.png);