Mac-letterhead is a Python module that provides a drag-and-drop interface for merging letterhead templates with PDF and Markdown documents.
The letterhead is applied 'under' the content, as if the document was printed on company stationery.

Key Features:
- Drag & drop interface for easy document processing
- Support for both PDF and Markdown input files
- Smart letterhead space detection to avoid content overlap (for Markdown)
- Multiple merging strategies (darken, multiply, overlay, etc.)
- Multi-page letterhead support (different designs for first/subsequent pages)

Usage Modes:
1. Install Mode:
   ```
   uvx mac-letterhead install /path/to/letterhead.pdf
   ```
   Creates a desktop application for drag-and-drop document processing

2. Direct Merge Mode:
   For PDF files:
   ```
   uvx mac-letterhead merge /path/to/letterhead.pdf "Title" output_dir input.pdf
   ```
   For Markdown files:
   ```
   uvx mac-letterhead merge-md /path/to/letterhead.pdf "Title" output_dir input.md
   ```

Current State:
- Fully functional PDF and Markdown document processing
- Smart margin detection for letterhead content
- Multiple merging strategies implemented
- Professional document formatting with proper spacing

# Developer information
Keep this package 'self contained' so that it relies only on components in the package.
Avoid relying on installed software packages outside, either python or brew.

Use - and update when necessary - make and the Makefile in the project root to test and publish the package.
Avoid making changes to tests/utils unless explicitely asked for, the utils are considered static and finished.