.bekkan-banner {
  display: flex;
  justify-content: center;
  margin: 70px 0 10px;
}

.bekkan-banner a img {
  display: block;
  margin: 0 auto;
  width: min(80%,650px);
  height: auto;
}

@media (min-width:750px) {
  .bekkan-banner {
    margin: 80px 0 40px;
  }

  .bekkan-banner a img {
    width: min(100%,650px);
  }
}