勾心斗角 — “To intrigue against each other”

The idiom "勾心斗角" (gōu xīn dòu jiǎo) originates from the Tang Dynasty poet Du Mu's famous work, "Ode to Afang Palace" (《阿房宫赋》).

Du Mu, deeply moved by the late Tang emperors' lavish construction and extravagant lifestyles, wrote this essay to subtly criticize the rulers of his time.

In describing the magnificent and intricate architecture of the Afang Palace, the original text vividly portrays its grandeur: "五步一楼，十步一阁。廊腰缦回，檐牙高啄。各抱地势，钩心斗角。" This translates to: "A tower at every five steps, a pavilion at every ten. Corridors loop and wind, eaves soar high like pecking beaks. Each embraces the terrain, with ingeniously interwoven and contending angles."

Originally, "钩心斗角" referred to the complex and interweaving structures of buildings, where corners and roofs seemed to hook and fight each other.

Over time, its meaning evolved to metaphorically describe people using all their cunning and schemes to compete and intrigue against each other, often in a covert or overt power struggle.