* {
  box-sizing: border-box;
}
:root {
  --hue: 220;
}
body {
  background: hsl(var(--hue), 100%, 5%);
  height: 100vh;
  overflow: hidden;
}
.star {
  --hue: 55;
  border-radius: 50%;
  background: hsl(var(--hue), 100%, 50%);
  box-shadow: 0 0 5px 1px hsl(var(--hue), 100%, 85%);
  height: calc(var(--size, 2) * 1px);
  position: absolute;
  width: calc(var(--size, 2) * 1px);
  left: calc(var(--x, 0) * 1vw);
  opacity: 0.5;
  top: calc(var(--y, 0) * 1vw);
  -webkit-animation: flicker calc(var(--duration, 2) * 1s) calc(var(--delay, 10) * 1s) infinite steps(1);
          animation: flicker calc(var(--duration, 2) * 1s) calc(var(--delay, 10) * 1s) infinite steps(1);
}
.lights {
  width: 100vmax;
  height: 100vmax;
  position: absolute;
  left: 50%;
  top: 0;
  transform: translate(-20%, -55%) rotate(30deg);
  display: flex;
  filter: blur(75px);
}
.light {
  flex: 1;
  --color-one: hsla(var(--hue-1), 100%, 50%, var(--alpha-1));
  --color-two: hsla(var(--hue-2), 100%, 50%, var(--alpha-2));
  --color-three: hsla(var(--hue-3), 100%, 50%, var(--alpha-3));
  --up: calc(var(--y, 10) * 2vmax);
  --left: calc(var(--x, 2) * 2vmax);
  background-image: linear-gradient(0deg, transparent, var(--color-one) 10%, transparent, var(--color-two) 40%, transparent, var(--color-three) 60%);
  background-size: 100% 40vmax;
  background-position: center bottom;
  background-repeat: no-repeat;
  transform: translate(var(--left), var(--up)) scale(1);
  -webkit-animation: shift calc(var(--duration, 2) * 1s) calc(var(--delay, 0) * -1s) infinite ease;
          animation: shift calc(var(--duration, 2) * 1s) calc(var(--delay, 0) * -1s) infinite ease;
}
@media (max-width: 768px) {
  .light {
    --up: calc(var(--y, 10) * 2vmax);
    --left: calc(var(--x, 2) * 2vmax);
  }
}
@-webkit-keyframes shift {
  50% {
    transform: translate(0, 0) scale(1);
  }
}
@keyframes shift {
  50% {
    transform: translate(0, 0) scale(1);
  }
}
@-webkit-keyframes flicker {
  0%, 50%, 100% {
    transform: scale(1);
  }
  25% {
    transform: scale(0);
  }
}
@keyframes flicker {
  0%, 50%, 100% {
    transform: scale(1);
  }
  25% {
    transform: scale(0);
  }
}


/* Aurora back */
article {
  position: absolute;
  opacity: 0.75;
}

@-webkit-keyframes hueRotate {
  to {
    filter: hue-rotate(360deg);
  }
}

@keyframes hueRotate {
  to {
    filter: hue-rotate(360deg);
  }
}
@-webkit-keyframes colour-1 {
  0% {
    top: 0vh;
    left: 50vw;
  }
  25% {
    left: 0vw;
  }
  50% {
    top: 100vh;
  }
  75% {
    left: 100vw;
  }
  100% {
    top: 0vh;
    left: 50vw;
  }
}
@keyframes colour-1 {
  0% {
    top: 0vh;
    left: 50vw;
  }
  25% {
    left: 0vw;
  }
  50% {
    top: 100vh;
  }
  75% {
    left: 100vw;
  }
  100% {
    top: 0vh;
    left: 50vw;
  }
}
@-webkit-keyframes colour-2 {
  0% {
    top: 50vh;
    left: 100vw;
  }
  25% {
    top: 100vh;
  }
  50% {
    left: 0vw;
  }
  75% {
    top: 0vh;
  }
  100% {
    top: 50vh;
    left: 100vw;
  }
}
@keyframes colour-2 {
  0% {
    top: 50vh;
    left: 100vw;
  }
  25% {
    top: 100vh;
  }
  50% {
    left: 0vw;
  }
  75% {
    top: 0vh;
  }
  100% {
    top: 50vh;
    left: 100vw;
  }
}
@-webkit-keyframes colour-3 {
  0% {
    top: 100vh;
    left: 50vw;
  }
  25% {
    left: 100vw;
  }
  50% {
    top: 0vh;
  }
  75% {
    left: 0vw;
  }
  100% {
    top: 100vh;
    left: 50vw;
  }
}
@keyframes colour-3 {
  0% {
    top: 100vh;
    left: 50vw;
  }
  25% {
    left: 100vw;
  }
  50% {
    top: 0vh;
  }
  75% {
    left: 0vw;
  }
  100% {
    top: 100vh;
    left: 50vw;
  }
}
.colour-1 {
  opacity:10%;
  box-shadow: 0 0 45vmax 45vmax purple;
  -webkit-animation: hueRotate 10s 0s linear infinite, colour-1 19s 0s linear infinite;
          animation: hueRotate 10s 0s linear infinite, colour-1 19s 0s linear infinite;
}

.colour-2 {
  opacity:10%;
  box-shadow: 0 0 45vmax 45vmax blue;
  -webkit-animation: hueRotate 15s 0s linear infinite, colour-2 25s 0s linear infinite;
          animation: hueRotate 15s 0s linear infinite, colour-2 25s 0s linear infinite;
}

.colour-3 {
  opacity:10%;
  box-shadow: 0 0 45vmax 45vmax red;
  -webkit-animation: hueRotate 20s 0s linear infinite, colour-3 15s 0s linear infinite;
          animation: hueRotate 20s 0s linear infinite, colour-3 15s 0s linear infinite;
}

@-webkit-keyframes fadeOut {
  to {
    opacity: 0;
  }
}

@keyframes fadeOut {
  to {
    opacity: 0;
  }
}