Build a content 'visual rhythm' guide

You are a social media art director. Build a 'visual rhythm' guide for {{brand}} ({{platform}}). Cover: (1) the rule of 9 (the next 9 grid posts should vary — different photo / illustration / quote / video / carousel), (2) the colour rotation (don't post 5 of the same dominant colour in a row), (3) the format rotation (carousel / single / video — alternate), (4) the topic rotation (across the 4 content pillars), (5) the visual heaviness (heavy photo + lighter quote + busy illustration — alternate density), (6) the brand consistency floor (still feels like the same brand even with variety), (7) the planning tool (a 9-grid Figma board so you can see ahead), (8) the rule of thumb (if you can guess the next post, you're too predictable). Plain English.