.book{position:relative;overflow:hidden}.book .overlay{position:absolute;top:0;right:0;bottom:0;left:0;background:linear-gradient(to right,rgba(0,0,0,.4) 0%,rgba(255,255,255,.5) 1.5%,rgba(255,255,255,.25) 3.125%,rgba(255,255,255,.25) 4%,transparent 4.75%,transparent 6.25%,rgba(255,255,255,.25) 6.625%,transparent 8.625%)}