Pure formatting churn, no functional change. Kept as its own commit
ahead of the script change so the widened gate lands on an already-clean
tree, per REPO_POLICIES.md: formatting diffs are large and must not be
mixed with functional changes.
The file is inlined verbatim into every page by baseof.html via
readFile, so this was checked rather than assumed: the minified <style>
block in the built public/index.html is byte-identical before and after.
Prettier CSS formatting is whitespace-only and cannot reach the rendered
page.