background: green;

background: content-box radial-gradient(crimson, skyblue);

background: no-repeat url("../../media/examples/lizard.png");

background: left 5% / 15% 60% repeat-x url("../../media/examples/star.png");

background: center / contain no-repeat url("../../media/examples/firefox-logo.svg"),
            #eee 35% url("../../media/examples/lizard.png");