@charset "UTF-8";
.loop {
  background-image: url(../img/top_main_mv.jpg);
  background-size: contain;
  width: 100%;
  background-size: cover;
  height: 250px;
  background-repeat: repeat-x;
  padding-top: calc(350 / 2000 * 100%);
  -moz-animation: loop 200s linear infinite;
  animation: loop 200s linear infinite;
}
/* 値が小さいほど早い↑ */

@keyframes loop {
  0% {
    background-position: 3924px 0;
  }
  25% {
    background-position: 2943px 0;
  }
  50% {
    background-position: 1962px 0;
  }
  75% {
    background-position: 981px 0;
  }
  100% {
    background-position: 0 0;
  }
}

@-moz-keyframes loop {
  0% {
    background-position: 3924px 0;
  }
  25% {
    background-position: 2943px 0;
  }
  50% {
    background-position: 1962px 0;
  }
  75% {
    background-position: 981px 0;
  }
  100% {
    background-position: 0 0;
  }
}

@media screen and (min-width: 551px) {
    .loop {
        height: 350px;
    }
}

@media screen and (min-width: 918px) {
    .loop {
        height: 550px;
    }
}