.parent{
	margin:10px;
	padding:10px;
	border:1px solid #ccc;
}
.child{
	margin:10px;
	padding:10px;
	width:200px;
	height:50px;
	font-size:16px;
	color:white;
}
:where(.parent1,.parent2) div{
	background-color:#0a0;
}