What are the creative characteristics of Tang poetry in the late Tang Dynasty?

The late Tang Dynasty is a period of gradual decline of Tang poetry. At first, there were two famous poets, Li Shangyin and Du Mu. They were called "Little Du Li". Their novels "A Hundred Rhymes in the Western Suburb" and "Poems for Feeling" have grand themes, which can inherit the similar works of Lao Du. Li Shangyin's seven methods and Du Mu's seven unique achievements are even higher. In the case that the Seven Laws have been excavated by predecessors in many ways and are almost unsustainable, Li Shangyin has sprung up suddenly and is unique. He made careful arrangements for language, antithesis, melody and allusions, and formed a rich and exquisite style, which became the brilliant sunset glow of Tang poetry. In particular, some "untitled poems" expressing love, such as the cloud "Spring silkworms die, and candles weep at night"; "Although my body doesn't have bright phoenix wings, I feel the harmonious heartbeat of the sacred unicorn", lingering feelings and hazy images give people a unique aesthetic feeling. Du Mu's Seven Musts are fresh and elegant, flowing, lively, simple in language and profound in meaning. Wang Changling, Li Bai and other quatrains can still form their own families.