@keyframes intro {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}
.seo-content {
  animation: intro 10s 0s 1 both;
}

body {
  min-height: 100vh;
  background-size: 100vh;
  background-attachment: fixed;
}

body.bg-1 {
  background: linear-gradient(180deg, #002288 0%, #000066 100vh);
}

body.bg-2 {
  background: linear-gradient(180deg, #880022 0%, #440044 100vh);
}

body.bg-3 {
  background: linear-gradient(180deg, #008822 0%, #006600 100vh);
}