body {
  display: grid;
  place-items: center;
  place-content: center;
  min-block-size: 100vh;
  font-family: system-ui, sans-serif;
}

h1.container {
  inline-size: 100vw;
  font-size: 30vmin;
  text-align: center;
  margin: 0;
  view-transition-name: fade;
}

::view-transition-old(fade) {
  animation: fade-out 2s;
}

::view-transition-new(fade) {
  animation: fade-in 2s;
}

@keyframes fade-in {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

@keyframes fade-out {
  from {
    opacity: 1;
  }

  to {
    opacity: 0;
  }
}