body{background:conic-gradient(from 90deg at 1px 1px,#0000 25%,#dcdcdc 0%) -.5px -.5px/1em 1em,linear-gradient(45deg,#0000 calc(50% - .5px),#dcdcdc 0 calc(50% + .5px),#0000 0) 0 0/2em 2em,linear-gradient(-45deg,#0000 calc(50% - .5px),#dcdcdc 0 calc(50% + .5px),#0000 0) 0 0/2em 2em;background-color:#eee}