I Transmigrated to Ancient Times, and the Empress Insists on Having My Child

It's a pity that I didn't finish it because of poor grades. Although the content is all old-fashioned (making inventions, modern economy, etc.), The plot is concentrated and the contradictions develop in an orderly manner. The most important thing is that the words and ink are appropriately arranged to depict the characters. The characters are also likable. The male protagonist is stable in his skin. The empress conceals her identity to complete the task and becomes emotionally involved step by step. Taoran's persistence and good style are all profound. Moreover, the characters are relatively concentrated, and several supporting characters have their own characteristics. There are only two beauties, the heroine and Tao Ran, in more than a hundred chapters, unlike some books with five or six harem candidates in a hundred chapters. It's a pity that I didn't finish it. Come on, author.