/* Shared design system for landing/help.html and landing/about.html — the subset of
index.html's own inline styles (tokens, reset, nav, buttons, footer) needed by simple
content pages. index.html keeps its own copy inline (it's a single page, and inlining
there removes a render-blocking request); this file exists because these two pages
would otherwise each duplicate the same ~150 lines. Keep in sync with index.html's