multi-devicelisted

# Multi-Device All web interfaces must work on: - Phone (375px width) — most important, many users are mobile-only - Tablet (768px width) - Desktop (1440px width) Rules: 1. Design mobile-first, scale up 2. Touch-friendly: buttons min 44px, enough spacing 3. No horizontal scrolling on any device 4. Text readable without zooming (min 16px body text) 5. Test at 375px viewport before declaring "done" Tell user: "手机和电脑都能用，你可以试试。"