RV-Utils__ElementAmount(amount, callback)
	if amount == 1
		&:only-child
			callback(i, amount)
	else
		*:first-child:nth-last-child({i}),
		*:first-child:nth-last-child({i})~*
			callback(i, up-to)

RV-Utils__ElementAmount--range(from=1, to=20, callback)
	for i in (from..to)
		RV-Utils__ElementAmount(i, callback)