{
  position: relative;
  width: 100%;
  height: 100vh;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}
 .wave {
  position: absolute;
  left: 0;
  width: 100%;
  height: 100%;
  background: #4973ff;
  box-shadow: inset 0 0 50px rgba(0, 0, 0, 0.5);
  transition: 0.5s;
}
 .wave span {
  content: "";
  position: absolute;
  width: 325vh;
  height: 325vh;
  top: 0;
  left: 50%;
  transform: translate(-50%, -75%);
  background: #000;
}

.wave span:nth-child(1) {
  border-radius: 45%;
  background: rgba(20, 20, 20, 1);
  animation: animate 5s linear infinite;
}

.wave span:nth-child(2) {
  border-radius: 40%;
  background: rgba(20, 20, 20, 0.5);
  animation: animate 10s linear infinite;
}
.wave span:nth-child(3) {
  border-radius: 42.5%;
  background: rgba(20, 20, 20, 0.5);
  animation: animate 15s linear infinite;
}
@keyframes animate {
  0% {
    transform: translate(-50%, -75%) rotate(0deg);
  }
  100% {
    transform: translate(-50%, -75%) rotate(360deg);
  }
}