html { background: url("https://img4.goodfon.com/wallpaper/nbig/2/39/tokho-toukhou-devushka-fon-mech.jpg") no-repeat center center fixed; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover; } .card { opacity: 0.9; } .blurry { backdrop-filter: blur(7px) !important; } pre code { color: #fff; background-color: #aaa; border: 1px solid #999; display: block; padding: 5px; overflow-x: auto; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word; }