Font Pairing: Flat Design Mobile (System Bold). Category: Sans + Sans. Heading Font: Inter. Body Font: Inter. Mood/Style: flat, clean, system, bold, geometric, cross-platform, icon, poster, minimal, functional, responsive. Best For: Cross-platform apps, dashboards, system UI, onboarding, marketing pages, informational apps, icon-heavy interfaces. Google Fonts URL: https://fonts.google.com/share?selection.family=Inter:wght@400;600;700;800. CSS Import: @import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;800&display=swap');. Tailwind Config: fontFamily: { sans: ['Inter', 'sans-serif'] }. Notes: System-first strategy: Inter as primary, falls back to system SF/Roboto on iOS/Android. Scale: Headlines fontWeight 800 letterSpacing -0.5; Subheadings fontWeight 600 fontSize 18; Body fontWeight 400 lineHeight 24; Labels fontWeight 700 uppercase letterSpacing 1. Thick weights carry all hierarchy since there are no shadows. Use aggressive size contrast (poster rule: body 16pt vs headline 40pt+). Avoid italic..