.diagonal-line{position:relative;overflow:hidden}.diagonal-line:before{content:"";-webkit-backdrop-filter:blur(1px);backdrop-filter:blur(1px);background:linear-gradient(to bottom left,#0000 calc(50% - 1px),red calc(50% - 1px) calc(50% + 1px),#0000 calc(50% + 1px));width:100%;height:100%;position:absolute;top:0;left:0}