body {
	--ball-dia: 100px;
}

.ball {
	width: var(--ball-dia);
	height: var(--ball-dia);
	border-radius: 50%;
	position: absolute;
	background-color: red;
	animation: big ease 0.1s;
}

.ball--first {
	left: calc(50vw - var(--ball-dia) * 0.5);
	top: calc(50vh - var(--ball-dia) * 0.5);
}

@keyframes big {
	from {
		transform: scale(0.5);
	}

	to {
		transform: scale(1);
	}
}

@-webkit-keyframes name {
	from {
		-webkit-transform: scale(0.5);
	}

	to {
		-webkit-transform: scale(1);
	}
}