html,
body {
  background-image: linear-gradient(to right, #ff0000, #0000ff);
  background-size: cover;
  background-repeat: repeat;
  animation: wave 2s linear infinite;
}

@keyframes wave {
  0% {
    background-position: 0 0;
  }
  50% {
    background-position: 100% 0;
  }
  100% {
    background-position: 0 0;
  }
}

html,
body {
  background-image: linear-gradient(to right, #ff0000, #0000ff);
  background-size: cover;
  background-repeat: repeat;
  background-attachment: solid;
  animation: wave 2s linear infinite;
}

h1 {
  background-image: linear-gradient(to bottom, #ff0000 0%, #0000ff 100%);
  text-fill-color: transparent;
  color: #fff;
  text-align: center;
  font-size: 20px;
}

div {
  background-image: linear-gradient(to bottom, #ff0000 0%, #0000ff 100%);
  text-fill-color: transparent;
  color: #fff;
  text-align: center;
  font-size: 20px;
}