One command makes every PNG and out/preview.html, and runs the checks: the profile circle (no logo pixel outside 0.42 x width; shown failing first on today's shape), the cover safe area (content inside what computer AND phone show, clear of the profile circle), and the sizes read back from the files. Exit 0 = all passed. Needs Python 3 + Pillow only. Brand source: website/assets/logo.png (the logo master — see below), website/assets/site.css tokens, website/assets/fonts/ (Plus Jakarta Sans).

What goes where

File	Where on the Page
`out/profile-dark.png` (recommended) or `out/profile-white.png`	Profile picture
`out/cover-a.png` / `cover-b.png` / `cover-c.png` — pick one	Cover photo
`COPY.md` §1	Intro / Bemutatkozás (≤ 100 characters)
`COPY.md` §2	About → details (longer description)
`COPY.md` §3	Messenger welcome message
`COPY.md` §4	The first three posts, each with its picture

Open out/preview.html (download it from Gitea, open locally — it is self-contained) to see each picture the way Facebook shows it.

Sizes used (READ, second-hand)

Meta's own help page (facebook.com/help/125379114252045) needs a browser and could not be read from DooPlex. Figures from size guides that quote it: cover shown 820 x 312 on computers and 640 x 360 on phones (built at 2 x: 1640 x 624); profile picture shown about 176 px; profile circle over the cover at 16 px / 176 px (computer) and 24 px / 196 px (phone). Sources: postfa.st/sizes/facebook/cover, linearity.io/templates/facebook-size-guide, fasturtle.com (faq-items/what-size-photos-do-i-use-on-facebook). Page about = 100 characters: developers.facebook.com/docs/graph-api/reference/page/ (Meta, first-hand).

The logo master

website/assets/logo.svg is not usable as a master: its „felhom.eu" lettering is live text in the fonts „M+ 2c" and „Vremena Grotesk", which DooPlex does not have, so any renderer here draws other letters. The PNG (645 x 408) is placed unscaled, so the profile picture is 932 x 932 — sharp, not enlarged. A vector master with the lettering converted to paths (Inkscape: Path → Object to Path, on the machine that has the fonts) is R-916.

Cover C

Uses website/assets/dashboard-backups-hu.webp (demo box, already public on the website). The demo box's domain chip next to the title is covered with the page colour in the copy; the source file is unchanged. No third-party logo appears in it (app names are text). The Launcher and Apps pictures were not used: they show app logos.