/* 追加CSS */
.oceans {
  width: 100%;
  height: 100%;
  position: relative;
}

.oceans img {
  width: 100%;
  height: auto;
}

.oceans__link {
  display: block;
  width: 100%;
  position: relative;
  transition: filter 0.3s ease;
}
.oceans__link:hover {
  filter: brightness(1.1);
}

@media (max-width: 768px) {
  .oceans {
    width: 100%;
    height: 100%;
    position: relative;
  }
}

.c-product__thum__inner {
  width: 100%;
  height: 100%;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  position: absolute;
  top: 50%;
  left: 50%;
  z-index: 1;
  transform: translate(-50%, -50%);
  height: 80%;
}