.workbook-content{background:rgba(211,211,211,0.5);padding:100px 20px}h1{font-size:1em}.wb-row{max-width:1200px;margin:auto;text-align:center}.wb-col{margin:10px;display:inline-block;vertical-align:top;text-align:left;-webkit-box-sizing:border-box;-moz-box-sizing:border-box;box-sizing:border-box}.thumb{width:450px;position:relative}.thumb .page{-webkit-box-shadow:0 0 3px 0 gray;-moz-box-shadow:0 0 3px 0 gray;box-shadow:0 0 3px 0 gray;height:100%;width:100%;position:absolute;background:white}.thumb img{width:100%;position:relative;z-index:100}