body, html {
  margin: 0;
  height: 100%;
  background: #05050f;
  overflow: hidden;
}

.sky {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.star {
  position: absolute;
  background: silver;
  border-radius: 50%;
  animation: fall linear infinite;
}

@keyframes fall {
  0% {
    transform: translateY(-10px);
    opacity: 0;
  }
  50% {
    opacity: var(--max-opacity);
  }
  100% {
    transform: translateY(105vh);
    opacity: 0;
  }
}