.banner-outer {
  width: 100%;
  margin-left: auto;
  margin-right: auto;
  max-width: 505px; 
  display: block;
  line-height: 0;
  transition: opacity 0.3s;
}

.banner-outer:hover {
  opacity: 0.8;
}

.banner-outer img {
  width: 100%;
  height: auto;
  display: block;
}

.banner-outer img.is-pc {
  display: block;
  padding-top: 20px;
}

@media (max-width: 809px) {
  .banner-outer img.is-pc {
    display: none;
  }
}

.banner-outer img.is-sp {
  display: none;
  padding-top: 30px;
}

@media (max-width: 809px) {
  .banner-outer img.is-sp {
    display: block;
    max-width: 350px; 
    margin: 0 auto;
  }
}