body {
  font-family: sans-serif;
  background: #64A1FF;
  background-repeat: no-repeat;
  height: 100vh;
  color: #fff;
  padding: 2em;
  overflow-y: hidden;
  text-shadow: 0 1px 1px #000;
}

h1 {
  font-size: calc( 24px + (72 - 24) * (100vw - 420px) / (980 - 420));
}
@media screen and (max-width: 420px) {
  h1 {
    font-size: 24px;
  }
}
@media screen and (min-width: 980px) {
  h1 {
    font-size: 72px;
  }
}

.texter {
  font-size: calc( 12px + (50 - 12) * (100vw - 420px) / (980 - 420));
  max-width: 980px;
  margin: auto;
}
@media screen and (max-width: 420px) {
  .texter {
    font-size: 12px;
  }
}
@media screen and (min-width: 980px) {
  .texter {
    font-size: 50px;
  }
}