body:before {
    content:"";
    position:absolute;
    inset:0;
    opacity:0.8;
    background:
            url('data:image/svg+xml;utf8,<svg style="transform:rotate(45deg)" xmlns="http://www.w3.org/2000/svg"  viewBox="0 0 50 60"><text x="0" y="25" fill="%23000">DEV</text></svg>')
            0 0/60px 60px;
}

body {
    position:relative;
    background:darkcyan;
    min-height:200vh;
}