* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: sans-serif;
}

section {
  position: relative;
  width: 100%;
  height: 100vh;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;

  .ondas {
    position: absolute;
    left: 0;
    width: 100%;
    height: 100%;
    background: #4973ff;
    box-shadow: 0 0 50px rgba(0, 0, 0, 0.5);
    transition: 0.5;

    span {
      content: "";
      position: absolute;
      width: 325vh;
      height: 325vh;
      top: 0;
      left: 50%;
      transform: translate(-50%, -75%);
      background: #000;

      &:nth-child(1) {
        border-radius: 45%;
        background: rgba(20, 20, 20, 1);
        animation: animate 15s linear infinite;
      }

      &:nth-child(2) {
        border-radius: 40%;
        background: rgba(20, 20, 20, 0.5);
        animation: animate 20s linear infinite;
      }

      &:nth-child(3) {
        border-radius: 42.5%;
        background: rgba(20, 20, 20, 0.5);
        animation: animate 25s linear infinite;
      }
    }
  }

  .content {
    position: relative;
    font-size: 4em;
    letter-spacing: 2pz;
    color: white;
    text-align: center;
    z-index: 1;
  }
}

@keyframes animate {
  0% {
    transform: translate(-50%, -75%) rotate(0deg);
  }

  100% {
    transform: translate(-50%, -75%) rotate(360deg);
  }
}