.s4_barrel {
position: relative;
display: block;
width: 982px;
margin-bottom: 20px;
left:-10px;
}

.header {
background: url(http://gigaplus.makeshop.jp/sdarts/project/s4_barrels/header.jpg) no-repeat;
position: relative;
display: block;
width: 982px;
height: 400px;
margin-bottom: 40px;
}
.header .mark01 {
background: none; 
display: block;
height: 400px;
text-indent: -9999px;
width: 327px;
float: left;
}
.header .mark02 {
background: none; 
display: block;
height: 400px;
text-indent: -9999px;
width: 327px;
float: left;
}
.header .mark03 {
background: none; 
display: block;
height: 400px;
text-indent: -9999px;
width: 327px;
float: left;
}


.item_01 {
background: url(http://gigaplus.makeshop.jp/sdarts/project/s4_barrels/1.jpg) no-repeat;
position: relative;
display: block;
width: 982px;
height: 800px;
margin-bottom: 40px;
margin-top: 40px;
}

.item_01 .btn_kounyuu {
position: absolute;
display: block;
top: 747px;
left: 745px;
width: 213px;
height: 38px;
}

.item_02 {
background: url(http://gigaplus.makeshop.jp/sdarts/project/s4_barrels/2.jpg) no-repeat;
position: relative;
display: block;
width: 982px;
height: 800px;
margin-bottom: 40px;
margin-top: 40px;
}

.item_02 .btn_kounyuu {
position: absolute;
display: block;
top: 747px;
left: 745px;
width: 213px;
height: 38px;
}

.item_03 {
background: url(http://gigaplus.makeshop.jp/sdarts/project/s4_barrels/3.jpg) no-repeat;
position: relative;
display: block;
width: 982px;
height: 880px;
margin-bottom: 40px;
margin-top: 40px;
}

.item_03 .btn_kounyuu {
position: absolute;
display: block;
top: 747px;
left: 745px;
width: 213px;
height: 38px;
}

.item_03 .btn_sonohoka {
position: absolute;
display: block;
top: 840px;
left: 350px;
width: 280px;
height: 38px;
}