.round_btn{display:block;position:absolute;top:-15px;right:-15px;width:30px;height:30px;border-radius:50%;background:#333}.round_btn:before,.round_btn:after{content:"";position:absolute;top:50%;left:50%;width:3px;height:21px;background:#fff}.round_btn:before{transform:translate(-50%,-50%) rotate(45deg)}.round_btn:after{transform:translate(-50%,-50%) rotate(-45deg)}.guide{animation:fadeIn 1s cubic-bezier(.33,1,.68,1) forwards;transition-delay:visibility3s;position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);-webkit-transform:translate(-50%,-50%);-ms-transform:translate(-50%,-50%);background-color:#00000080;color:#fff;width:300px}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}