Resize 159-Page PDF Book

I have a finished 159-page children’s colouring book saved only as a single PDF. The pages were designed in Canva at a larger size and now need to be resized to A4 (8.3 × 11.7 inches). I want every page to look exactly the same after the resize—no cropping, shifting, or enlarging of the drawings—just a clean scale-down so the artwork sits on an A4 canvas.

What I will send you
• The original 159-page PDF.

What I need back
• A print-ready PDF with all 159 pages resized to A4.
• Same page order, same resolution, and no loss of image quality.

The task should be straightforward for someone comfortable with Adobe Acrobat Pro, InDesign, Affinity Publisher, or similar PDF tools. Please let me know your turnaround time and a reasonable quote; I’m looking to keep costs low for this simple scaling job.