.fluid {
  width: 40vh; /*横幅*/
  height: 45vh; /*縦幅*/
  background: #ecec59; /*背景色*/
  animation: fluidrotate 30s ease 0s infinite; /*アニメーションの設定*/
  /* margin: 40vh 0 0 auto; */
  z-index: -10;
  position: absolute;
  top: 30vh;
  right: 27vw;
}

@keyframes fluidrotate {
  0%,
  100% {
    border-radius: 63% 37% 54% 46%/55% 48% 52% 45%;
  }
  14% {
    border-radius: 40% 60% 54% 46%/49% 60% 40% 51%;
  }
  28% {
    border-radius: 54% 46% 38% 62%/49% 70% 30% 51%;
  }
  42% {
    border-radius: 61% 39% 55% 45%/61% 38% 62% 39%;
  }
  56% {
    border-radius: 61% 39% 67% 33%/70% 50% 50% 30%;
  }
  70% {
    border-radius: 50% 50% 34% 66%/56% 68% 32% 44%;
  }
  84% {
    border-radius: 46% 54% 50% 50%/35% 61% 39% 65%;
  }
}