.box{
width: 980px;
height: auto;
clear: both;
overflow: hidden;
margin: 20px auto;
}
.box li{
width: 300px;
height: 210px;
float: left;
background: white;
margin: 20px 10px;
border: 2px solid #efefef;
box-shadow: 0 1px 4px rgba(0,0,0,0.27),0 0 60px rgba(0,0,0,0.1) inset;
position: relative;
}
.box li img{
display: block;
width: 290px;
height: 200px;
margin: 5px;
}
.box li:before{
content:
''
;
z-index: -1;
position: absolute;
width: 90%;
height: 80%;
left: 20px;
bottom: 8px;
background:transparent;
box-shadow: 0 8px 20px rgba(0,0,0,0.6);
transform: skew(-12deg) rotate(-4deg);
}
.box li:after{
content:
''
;
z-index: -1;
position: absolute;
width: 90%;
height: 80%;
right: 20px;
bottom: 8px;
background:transparent;
box-shadow: 0 8px 20px rgba(0,0,0,0.6);
transform: skew(12deg) rotate(4deg);
}