What do you mean that the Yuan Dynasty was independent and had a Song ethos?

Fisherman Wang in the early Song Dynasty was a pioneer of literary creation in the Song Dynasty. Song Chao said that "the Yuan Dynasty was independent and had a Song ethos". Among them, "Yuan Zhi" refers to Wang Yucheng, and the unique style of Yuanqu refers to that the poems of Wang Yufu in the early Song Dynasty were inspired by Bai Juyi, who was the first person to create the literary style of the Song Dynasty. Wang Yucheng, the pioneer of the poetry innovation movement in the Northern Song Dynasty, praised Du Fu and Bai Juyi in literature, and his style was fresh and simple. There is only one poem left, which reflects the author's political ambition to actively use the world and has a fresh and broad style. He is the author of Small Livestock Collection and History of Five Dynasties.