.top-page {
  position: relative;
  z-index: 1;
}
.top-page::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  z-index: -1;
  width: 100%;
  aspect-ratio: 1920/734;
  background: url('../images/top/mv-bg.webp') center / cover no-repeat;
  mix-blend-mode: overlay;
}