This question was related to the plot and theme of the novel. According to the plot and theme of the novel, I can provide the following possible answers: - The structure of the villa could be designed according to the "rain" because the story background was a rainy day or the protagonist liked the rain and hoped that the exterior design of the villa would complement the rain. This kind of plot setting could create a suspense and mysterious atmosphere to increase the reader's interest in reading. - The structure of the villa could be designed according to "rain" because the story background was that the protagonist needed to return to the villa after the rain and found that something strange had happened in the villa. This kind of plot setting could bring a tense and exciting atmosphere to increase the reader's reading experience. - The structure of the villa can be designed according to the "rain" because the story background is a fictional world. The structure of the villa is similar to the real world so that readers can easily understand the plot and background of the story. This kind of plot setting could enhance the fiction and creativity of the novel. These are some of the possible answers I can provide, hoping to inspire your imagination.