% Shared preamble: packages, fonts, page geometry.
% Kept intentionally minimal — every package here is mainstream and stable.

\usepackage{fontspec}
\usepackage{geometry}
\usepackage{titlesec}
\usepackage{enumitem}
\usepackage{hyperref}
\usepackage{xcolor}
\usepackage{ragged2e}
\usepackage{fancyhdr}

% Fonts: Source Serif/Sans if available, fall back to TeX Gyre (Termes/Heros).
% TeX Gyre ships with every TeX Live install, so this compiles anywhere.
% To force Source fonts on your own machine, just ensure they're installed
% system-wide or via TeX Live's fontspec search path.
\IfFontExistsTF{Source Serif Pro}{
  \setmainfont[Ligatures=TeX, Numbers={Lining,Proportional}]{Source Serif Pro}
}{
  \setmainfont[Ligatures=TeX, Numbers={Lining,Proportional}]{TeX Gyre Termes}
}

\IfFontExistsTF{Source Sans Pro}{
  \newfontfamily\headerfont[Ligatures=TeX, Numbers={Lining,Proportional}]{Source Sans Pro}
}{
  \newfontfamily\headerfont[Ligatures=TeX, Numbers={Lining,Proportional}]{TeX Gyre Heros}
}

% Black-and-white color palette. `linkcolor` stays black for print-conservative
% output; the URL is still clickable in PDF readers.
\definecolor{headerblack}{gray}{0.0}
\definecolor{rulegray}{gray}{0.15}
\definecolor{metagray}{gray}{0.35}

\hypersetup{
  colorlinks=true,
  linkcolor=black,
  urlcolor=black,
  citecolor=black,
  pdfborder={0 0 0}
}

% No paragraph indent, small inter-paragraph space.
\setlength{\parindent}{0pt}
\setlength{\parskip}{0.35em}

% Tight list defaults — itemize blocks should feel controlled, not sprawling.
\setlist[itemize]{
  leftmargin=1.2em,
  topsep=0.2em,
  itemsep=0.25em,
  parsep=0pt,
  label={\small\textbullet}
}