What are the characteristics of late Tang poetry?

In the middle and late Tang dynasty, the heyday of the dynasty has passed, but poetry creation has not declined. Outstanding poets with different styles have emerged, such as Han Yu, Liu Zongyuan, Zhang Ji, Li He, Bai Juyi, Yuan Zhen, Liu Yuxi, Du Mu, Li Shangyin, Wen and Du Xunhe. Their poems reflect the crisis and folk sufferings in the decline of the Tang Dynasty empire from different angles, and their artistic achievements are very high, which have a great influence on future generations.