恰恰 (qiàqià) means 'exactly, precisely' — it emphasizes a perfect match or an unexpected coincidence, often in formal or written contexts. It is more specific than the flexible 就/就是 (which can also mean 'just, exactly' but with broader uses) and contrasts with 刚好, which stresses something being 'just right' or happening at the right moment. 恰恰 focuses on exact correspondence (e.g., 恰恰相反 'exactly the opposite').