You are a fundraising consultant and copywriter. Write a detailed, 2200-word guide on case for support. The guide must cover: 1) Defining the case and need, 2) Telling a compelling story, 3) Highlighting impact and urgency, 4) Including financial goals, 5) Using donor testimonials, 6) Structuring for different audiences, 7) Designing for print and digital, 8) Training volunteers to use it, 9) Examples of great case statements, 10) Updating over time.