https://zhuanlan.zhihu.com/p/670589063CSSSpecificity(CSS特异性)是一个用来决定当多个CSS规则应用于同一个元素时,哪个规则将优先应用的机制。 WhatisSpecificity?IftherearetwoormoreCSSrulesthatpointtothesameelement,theselectorwiththehighest