.hero_section {
  position: relative;
}

.starry_sky {
  background: linear-gradient(to bottom, rgb(9, 8, 30) 40%, rgb(3, 29, 54) 80%, rgb(1, 29, 74));
  width: 100%;
  height: 100vh;
  position: absolute;
  overflow: hidden;
  z-index: -1;
}

.constellation {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  animation: rotate 500s infinite linear;
  z-index: 1;
  opacity: 1;
}

.star {
  background-color: white;
  border-radius: 50%;
  position: absolute;
  animation-timing-function: linear;
  animation-iteration-count: infinite;
}

.star.style1 { animation-duration: 6s; animation-name: star; }
.star.style2 { animation-duration: 5.5s; animation-name: star; }
.star.style3 { animation-duration: 4s; animation-name: star; }
.star.style4 { animation-duration: 4.5s; animation-name: starFeat; }

.star.tam1 { width: 1px; height: 1px; }
.star.tam2 { width: 2px; height: 2px; }
.star.tam3 { width: 1px; height: 1px; }

.star.opacity1 { opacity: 1; }
.star.opacity2 { opacity: 0.5; }
.star.opacity3 { opacity: 0.1; }

@keyframes star {
  0%, 100% { box-shadow: 0 0 5px 0px rgba(255, 255, 255, 0.05); }
  50% { box-shadow: 0 0 5px 3px rgba(255, 255, 255, 0.4); }
}

@keyframes starFeat {
  0% {
    background-color: #FFFFFF;
    box-shadow: 0 0 15px 0px rgba(255, 255, 255, 1);
  }
  20% {
    background-color: #FFC4C4;
    box-shadow: 0 0 10px 0px rgba(255, 196, 196, 1);
  }
  80% {
    background-color: #C4CFFF;
    box-shadow: 0 0 10px 0px rgba(196, 207, 255, 1);
  }
  100% {
    background-color: #FFFFFF;
    box-shadow: 0 0 15px 0px rgba(255, 255, 255, 0.2);
    }
  }

  @keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
  }

  .logo-warp {
      position: relative;
    }

    .hoshigaoka_w_logo {
      position: absolute;
      width: 100%;
      max-width: 350px;
      height: auto;
      top: 50vh;
      left:50%;
      transform: translate(-50%, -50%);
      opacity: 0;
      transition: opacity 1s ease;
      display: block;
    }
    .hoshigaoka_w_logo img {
      width: 100%;
    }

@media screen and (max-width: 1024px) {
  .hoshigaoka_w_logo {
    max-width: 250px;
  }
}
@media screen and (max-width: 619px) {
  .hoshigaoka_w_logo {
    max-width: 150px;
  }
}