.flicker-slow{
  animation: flicker 4s linear infinite;
}

.flicker-fast{
  animation: flicker 2s linear infinite;
}

@keyframes flicker {
	0%, 19%, 22%, 62%, 64%, 65%, 70%, 100% {
    opacity: 1.0;
		
	}
	20%, 21%, 63%, 64%, 65%, 69% {
		opacity: 0.5;
	}
}