Flat Design System Skill guides an agent to create practical, implementation-ready design guidance focusing on a two-dimensional minimalist style with vibrant colors, clean typography, and no 3D effects. It provides structured style foundations, accessibility requirements, writing tone rules, and an authoring workflow covering tokens, components, and QA checklists. Reach for it when you need to generate structured design system documentation, component rules, and accessibility criteria adhering to modern web standards.