Here the "heart" represents the whole person, emphasizing the person's thoughts. Alternate translation: "You were arrogant" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
The abstract nouns "beauty," wisdom" and "splendor" can be translated using the adjectives "beautiful," "wise" and "splendid." Alternate translation: "Your heart was arrogant because you were beautiful; you became unwise because you were so splendid" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])