Confusing description at end of this page

Salut ! The reason given for the adverbs not matching in gender and number is because 'they do not have gender', but neither do adjectives, which are matching the noun they refer to I believe- so is there another way for us to describe it? Like; adjectives refer to nouns, and adverbs refer to verbs, (verbs have no gender). This kept confusing me, every time i re-read it, Cheers