What is the mainstream of literature in Tang, Song and Yuan Dynasties?

Five-character poems and seven-character poems are the most popular poems in the middle period of Tang Jianguo. After the mid-Tang Dynasty, Liu Zongyuan and Han Yu began to write ci, fu and preface, and began to write ci (Song Ci) after the Song Dynasty, which reached its peak. At this time, the ancient prose "Ji, Fu and Xu" had a certain status, but its popularity was far less than that of Song Ci and Song Ci.