:root {
  --planet-z-step: -100px;
  --planet-y-step: -50px;
  --planet-total: 10;
}

.reference {
  width: 100%;
  height: 100vh;
  position: relative;
  overflow: hidden;
}

.planet_container {
  position: relative;
  z-index: 10;
  width: 100%;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  perspective: 1200px;
  opacity: 0;
  transition: all 1s cubic-bezier(0.23, 1, 0.32, 1);
}
.planet_container .planet_wrap {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
}
.planet_container .planet_wrap .swiper-wrapper {
  transform-style: preserve-3d;
  will-change: transform;
}
.planet_container .planet_wrap .swiper-slide {
  transform-style: preserve-3d;
  will-change: transform, opacity;
  backface-visibility: hidden;
  pointer-events: auto;
}
.planet_container .planet_box {
  position: relative;
  width: 80%;
  max-width: 1000px;
  height: 900px;
  margin: 0 auto;
  transform-style: preserve-3d;
  cursor: pointer;
  pointer-events: auto;
  will-change: transform;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  transform: translate3d(0, 0, 0);
}
.planet_container .planet_box .planet {
  width: 100%;
  height: 550px;
  border-radius: 10px;
  position: relative;
  background: #111;
  margin: 0 auto;
  transform-style: preserve-3d;
  opacity: 1;
  transition: all 0.5s ease;
  box-shadow: 0 0 20px rgba(255, 255, 255, 0.2);
  overflow: hidden;
  will-change: transform, opacity;
}
.planet_container .planet_box .planet img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
}
.planet_container .planet_box .planet img.pc {
  display: block;
}
.planet_container .planet_box .planet img.mobile {
  display: none;
}
.planet_container .planet_box .planet:hover {
  box-shadow: 0 0 30px rgba(0, 255, 0, 0.3);
}
.planet_container .planet_box .planet_info {
  padding: 20px 0;
  text-align: center;
  color: #fff;
  font-size: 20px;
  transform: translateZ(0);
  will-change: transform;
}

@media (max-width: 600px) {
  .reference .planet_container .planet_wrap {
    height: 100vh;
  }
  .reference .planet_container .planet_wrap .planet_box {
    width: 75%;
    margin: 0 auto;
    height: 100vh;
  }
  .reference .planet_container .planet_wrap .planet_box .planet {
    border-radius: 10px;
    overflow: hidden;
    height: auto;
    width: 100%;
    aspect-ratio: 1/1;
  }
  .reference .planet_container .planet_wrap .planet_box .planet img.pc {
    display: none;
  }
  .reference .planet_container .planet_wrap .planet_box .planet img.mobile {
    display: block;
    height: 100%;
    object-fit: cover;
    aspect-ratio: 1/1;
  }
  .reference .planet_container .planet_wrap .planet_box .planet_info {
    font-size: 16px;
  }
}