.mv-slick .img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  position   : absolute;
  top        : 0;
  left       : 0;
  bottom     : 0;
  right      : 0;
  opacity    : 0;
  animation  : bgAnime 18s infinite;   /* 4画像 × 各5s = 20s */
}
.mv-slick #src1{
  background-image: url('../images/mv1.png');
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
}
.mv-slick #src2{
  background-image: url('../images/mv2.png');
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  animation-delay  : 6s;
}
.mv-slick #src3{
  background-image: url('../images/mv3.png');
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  animation-delay  : 12s;
}
@media screen and (max-width: 500px){
  .mv-slick #src1{
  background-image: url('../images/mv1sp.png');
}
.mv-slick #src2{
  background-image: url('../images/mv2sp.png');
}
.mv-slick #src3{
  background-image: url('../images/mv3sp.png');
}
}

@keyframes bgAnime {
   0% { opacity: 0; }
   33% { opacity: 1; }
  66% { opacity: 0; }
 100% { opacity: 0; }
}