<style>
    body {
      background-image: url("https://http.cat/404.jpg");
      background-position: center;
      background-repeat: repeat;
      animation: scrolling 7.5s linear 1;
      animation-direction: forward;
      animation-iteration-count: infinite;
    }
    @keyframes scrolling {
    0% {
        background-position: 0 0;
    }
    100% {
        background-position: -750px 600px;
    }
}
</style>