You are a UX designer. Develop a comprehensive guide to empty state design. The guide must cover: 1) Types (first use, cleared, no results, errors), 2) Visual elements (illustration, icon), 3) Copywriting (helpful, encouraging, clear), 4) Call-to-action buttons, 5) Educational content, 6) Personality and brand, 7) Animation, 8) Examples for different contexts, 9) Testing empty states, 10) Best practices. Provide design examples.