* {
  margin: 0;
  padding: 0;
}
body {
  min-height: 100vh;
  display: grid;
  place-items: center;
  background-color: #1e272e;
}

.wave {
  position: relative;
  width: 500px;
  height: 500px;
  transform-style: preserve-3d;
  transform: perspective(800px) rotateX(60deg);
}
.wave div {
  position: absolute;
  display: block;
  border: 10px solid #fff;
  box-shadow: 0 8px 0 #ccc;
  border-radius: 50%;

  animation: wave 3s ease-in-out infinite;
  top: calc(var(--i) * 10px);
  left: calc(var(--i) * 10px);
  bottom: calc(var(--i) * 10px);
  right: calc(var(--i) * 10px);
  animation-delay:calc(var(--i) * 0.1s) ;
}

@keyframes wave {
  0%,
  100% {
    transform: translateZ(-120px);
  }
  50% {
    transform: translateZ(120px);
  }
}