:root {
  font-family: 'Ruder Plakat', sans-serif;
  font-size: 50vh;
}

body { /* hier braucht es eher keinen Raster */
  background-color: #1D1D1D; 
  text-align: center;
  animation: rainbow-animation 1s linear infinite alternate; 

}

span { /* hier raster*/
  line-height: 0.5px;
  animation: anim1 2s linear infinite alternate; 

}

@keyframes anim1 {
  0% {font-variation-settings: "YTUC" 100;}
  100% {font-variation-settings: "YTUC" 900;}
}

@keyframes rainbow-animation {
  0% {
    background-color: red;
  }
  20% {
    background-color: orange;
  }
  40% {
    background-color: yellow;
  }
  60% {
    background-color: green;
  }
  80% {
    background-color: blue;
  }
  100% {
    background-color: violet;
  }
}