body.index main .mv {
  background: url(/static/full/tnf/special/explorer_band_vol1/assets/img/index/mv.jpg) center center/cover no-repeat;
}
@media only screen and (max-width: 767px) {
  body.index main .mv {
    background: url(/static/full/tnf/special/explorer_band_vol1/assets/img/index/mv_sp.jpg) center center/cover no-repeat;
  }
}