.contents .main .slide-1:before {
  background: #eee url(http://img.sokcho-port.co.kr/intro/m/mv_1.jpg) no-repeat center 80% / cover;
}

.contents .main .slide-2:before {
  background: #eee url(http://img.sokcho-port.co.kr/intro/m/mv_2.jpg) no-repeat center 100% / cover;
}