.site_left {
	float: left;
	width: 300px;
	margin-left: 50px;
}
.site_right {
	float: right;
	width: 355px;
}
.site01 {
	width: 710px;
	margin-right: 35px;
	margin-left: 30px;
	height: 270px;
}
.site02 {

	width: 710px;
	margin-right: 35px;
	margin-left: 30px;
	height: 300px;
}
.site03 {


	width: 710px;
	margin-right: 35px;
	margin-left: 30px;
	height: 200px;
}
#bucktop { 
　　width:DIVの横幅x;
　　height:DIVの高さ;
　　position:fixed;
　　z-index:1;
　　top: 50px;
　　right: 0px;
}