.sdvx_body {
  width:100%;
  height:auto;
  background-color:#fff;
}
@media (min-width: 980px){
.sdvx_main {
  width:980px;
  height:auto;
  margin:0;
}}
@media (max-width: 979px){
.sdvx_main {
  width:100%;
  height:auto;
  margin:0;
}}
.sdvx_sub {
  display:block;
  width:100%;
  height:auto;
  background-color:#fff;
}
@media (min-width: 340px){
.sdvx_sub #img_box {
  width:320px;
  height:auto;
  margin:8px 2px;
  float:left;
}
}
@media (max-width: 339px){
.sdvx_sub #img_box {
  width:90%;
  height:auto;
  margin:8px;
  float:left;
}
}

.back_btn {
  position:absolute;
  display:block;
  width:35%;
  height:65px;
  top:90px;
  left:0;
  z-index:50;
  //border:solid 1px #f00;
}

.clear{
  clear: both;
}