.si-background {
  background: linear-gradient(127deg,#212529,#1493b4,#4f210f);
  background-size: 180% 180%;
  animation: si-animation 27s ease infinite;
}

@keyframes si-animation {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

.rt-background {
  background: linear-gradient(158deg,#195f3f,#b38f02,#4df9f8,#49486d,#56b0ef,#c8dd2b);
  background-size: 360% 360%;
  animation: rt-animation 48s ease infinite;
}

@keyframes rt-animation {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

.sd-background {
  background: linear-gradient(144deg,#0f1c3a,#133359,#165279,#177c9b,#16b2bf,#13e5d5);
  background-size: 360% 360%;
  animation: sd-animation 36s ease infinite;
}

@keyframes sd-animation {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

.pr-background {
  background: linear-gradient(45deg,#B0B8C6,#D8D8DA,#F0F4F7,#fafafa);
  background-size: 360% 360%;
}