\usepackage{xcolor}
\usepackage{fontspec}
\usepackage[sc]{mathpazo}
\setmainfont[Ligatures=TeX]{Palatino Linotype}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{menukeys}
\definecolor{darkblue}{rgb}{0,0,0.6}
\usepackage[colorlinks=true,urlcolor=darkblue,linkcolor=darkblue]{hyperref}

\newcommand{\dn}{\stackrel{\mbox{\scriptsize def}}{=}}%
\definecolor{codegray}{gray}{0.9}