/* 泡上がる */
.soda {
  position:fixed;
  top:0;
  right:0;
  bottom:0;
  left:0;
  perspective:50vw;
  transform:translateZ(-99999px);
  transform-style:preserve-3d;
  z-index:10001;
  pointer-events:none
}
.bubble {
  position:absolute;
  width:50px;
  height:50px;
  border-radius:50%;
  background-image:url(../img/bubble-01.png);
  background-size:100%;
  transform:translateX(-50%);
  will-change:top,left
}