What are the different characteristics of Yuan poetry in different periods?

Most of the poets in the early Yuan Dynasty were adherents of the Song and Jin Dynasties, and most of them experienced social changes of changing dynasties. Therefore, some poems by writers such as Liu Yin and Zhao can profoundly reflect social contradictions and national consciousness. After the middle period, the society tends to be relatively stable, and the resumption of the imperial examination gives intellectuals a chance to enter the world. Taoism, especially in the Song Dynasty, played the role of "governing the mind as a golden yuan" (Lu Xun's language), and many poets were also Neo-Confucianism. Together with Yu Ji, Yang Zai, Frant Gwo and Guo Jie, they are called "Four Poets of Yuan Dynasty". Important poets in the later period include Wang Mian and Yang Weizhen. Their works are more exposed to the sharp social contradictions at the end of the Yuan Dynasty, and their styles are more diverse.