.clearfix:after {
	clear: both;
	display: table;
	content: '';
}
#b, #c, #d {
	margin-top: 10px;
}
#a {
	margin: 0 auto;
	width: 958px;
}
#b>div {
	border: 1px lightgray solid;
	height: 50px;
	width: 472px;
	float: left;
	margin-right: 10px;
	box-shadow:2px 2px 2px #eee;
}
#b>div:last-child {
	margin-right: 0;
}
#c>div {
	border: 1px lightgray solid;
	height: 60px;
	float: left;
	margin-right: 10px;
	box-shadow:2px 2px 2px #eee;
}
#c>div:last-child {
	margin-right: 0;
}
#c1 {
	width: 231px;
}
#c2 {
	width: 470px;
}
#c3 {
	width: 231px;
}
#d {
	border: 1px lightgray solid;
	height: 30px;
	box-shadow:2px 2px 2px #eee;
}