wp-calypso/client/components/animate/style.scss

.animate__appear {
	animation: animate__appear 600ms cubic-bezier(0.1, 0.82, 0.25, 1);
	transform-origin: center center;
}

@keyframes animate__appear {
	0%,
	20% {
		transform: scale(0, 0);
	}
	100% {
		transform: scale(1, 1);
	}
}

.animate__fade-in {
	animation: fade-in 0.5s ease-out;
	animation-fill-mode: forwards;
}

@keyframes fade-in {
	from {
		opacity: 0;
		transform: scale(0.92);
	}
	to {
		opacity: 1;
		transform: scale(1);
	}
}