Expresses 'the more ~, the more ~'; a proportional relationship between two phrases.
Verb-casual + ば + Verb-casual + ほど, い-Adjective + ば + い-Adjective + ほど, な-Adjective + であれば + な-Adjective + ほど
Long explanation:
The ~ば~ほど grammar point is used to express a proportional relationship between two phrases, meaning 'the more A, the more B'. The formation differs depending on whether it is used with a verb, い-adjective, or な-adjective.