\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}
\newcommand\grid[1]{%
\begin{tikzpicture}[baseline=(char.base)]
\path[use as bounding box]
(0,0) rectangle (1em,1em);
\draw[red!50, fill=red!20]
(0,0) rectangle (1em,1em);
\node[inner sep=1pt,anchor=base west]
(char) at (0em,\gridraiseamount) {#1};
\end{tikzpicture}}
\newcommand\gridraiseamount{0.12em}
\makeatletter
\newcommand\Grid[1]{%
\@tfor\z:=#1\do{\grid{\z}}}
\makeatother
\makeatletter
\def\fnote{\gdef\@thefnmark{}\@footnotetext}
\makeatother