.main{   
width:670px;
height:670px;
position:absolute;
left:50%;
top:50%;
margin:-335px 0 0 -335px;
}

body {
	background-color: #fff;
	margin:0;
    height:100%;
}

.art {
    float: left;
    width: 50%;
    height: 20%;
    background: #FF8800;
}

.photo {
    float: left;
    width: 50%;
    height: 20%;
    background: #000;
}

.dada {
    width: 100%;
    height: 80%
}