devpageA PDF is the page the browser shows
devpage pdf makes a PDF by having Chrome print the page devpage serves, in
print mode. Print mode differs from the screen only by what it leaves out
— live updates, comments, a site's sidebar or a doc's outline, a deck's
controls, soft shadows — and by its @page size. It renders the same Markdown with the same
stylesheet, the same highlighted code and the same diagrams. There is no second
renderer for paper.
Why
A second renderer is a second implementation of every Markdown feature, every diagram and every theme token, and the two drift: the PDF a reviewer signs off is no longer the page the author wrote. A deck laid out at a fixed 1920 × 1080 and only scaled to the window prints exactly as it shows; one that reflows to the window does not.
Check
Print-mode differences live in the stylesheet's @media print rules
and in leaving parts out of the frame — never in a separate HTML path or
Markdown pass. A test prints the example doc and the example deck and finds
one page per slide at 16:9, and the doc's header and footer on its pages.