fxcss tweaks

fxcss tweaks
fxcss tweaks --combo compact-tabs+tabs-swapclose

Document your install options with screenshots. Themes describe their optional stylesheets in prose — accordions of flags, install.sh -c -n -s incantations — and a user assembles their preferred setup in their head. This renders the answer instead: the base theme, every optional stylesheet, and any combination you bless with --combo, each with a labelled before/after crop of the region it actually changes and how much of the chrome it touches.

A --combo is also judged against its own parts: if a+b renders pixel-identically to b alone, then a did nothing in that combination, and TWEAKS.md says so rather than presenting the pair as a real option. That is the check the static conflict analysis in install cannot make — two sheets can fight over the same pixels through entirely different rules — and the rendered images settle it as a fact rather than a judgement.

The crop is built from the changed pixels, so it needs no per-option configuration and cannot drift when Firefox moves something. It centres on the busiest cluster of changes rather than the bounding box of all of them, which is what makes the common cases readable: swapping the tab close button changes every tab, and a crop of all of them is the tab strip again, shrunk until nothing is visible. One tab, magnified, shows the option. Panels scale up as well as down for the same reason — a correctly cropped 16px button is still a 16px button.

The output is a folder of PNGs plus TWEAKS.md, written to be committed: relative links, and a <details> accordion per option so a long list stays scannable on GitHub. If your README documents installer flags, they are parsed and included as a table.

A tweak that changes nothing in the captured state is reported as exactly that — "changes nothing on current Firefox, possibly stale". Optional sheets rot at least as fast as selectors do, and nobody notices because nobody has them enabled.