A single code file must have ≤ 300 lines. This is a mandatory restriction with no exceptions.

• Check timing: When creating a new file, after modifying an existing file
• Overlimit handling: Must be split immediately, discuss the solution with the user before splitting
• Prohibited actions: ❌ Exceeding 300 lines on grounds such as "complex functions" is not allowed

1. Check the number of lines immediately
2. If it exceeds 300 lines, must stop and propose splitting suggestions
3. Provide a specific splitting plan (file list, responsibility division)

• Check whether all relevant files have ≤ 300 lines
• Must point out immediately if overlimit files are found

• All files have ≤ 300 lines (mandatory requirement)
• Each file has clear responsibilities after splitting

• references/splitting-guide.md

  - Detailed guide to file splitting (splitting principles, processes, common patterns)