.epidemic-top {
  width: 100%;
  position: relative;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1;
  overflow: hidden;
}
.bg-img img {
  width: 100%;
  margin: 0 auto;
}
#appImg{
  display:none;
}
.video-slide{
  margin-top:0;
}
@media (max-width:767px){
  #appImg{
    display:block;
  }
  #pcImg{
    display:none;
  }
}