.day-card.crossed:before{content:"";position:absolute;top:10px;left:10px;bottom:10px;right:10px;background:linear-gradient(to top right,rgba(0,0,0,0),rgba(0,0,0,0) calc(50% - 1px),#A8A8A8 50%,rgba(0,0,0,0) calc(50% + 1px),rgba(0,0,0,0))}.day-card.crossed>*{z-index:1}