body {
  background-image: url(../images/second/secnd_bg_pc.jpg);
  background-repeat: no-repeat;
  background-size: cover;
}

@media (max-width: 1199px) {
    body {
        background-image: url(../images/second/secnd_bg_sp.jpg);
        background-repeat: no-repeat;
        background-size: cover;
    }
}