.bubbles {
  position: absolute;
  inset: 0;
  pointer-events: none;
  /* z-index: 1; */
}

/* 泡の見た目 */
.bubble {
  position: absolute;
  bottom: -5vh;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
   border: 1px solid white;
  box-shadow: 0 0 5px rgba(255, 255, 255, 0.8);
  animation: rise linear forwards;
}