preamble.tex

\usepackage{booktabs}
\usepackage{amsthm}
\makeatletter
\def\thm@space@setup{%
  \thm@preskip=8pt plus 2pt minus 4pt
  \thm@postskip=\thm@preskip
}
\makeatother

% Match code width in O'Reilly books
\setmonofont[Mapping=tex-ansi]{Inconsolata}
\usepackage{anyfontsize}
\DefineVerbatimEnvironment{Highlighting}{Verbatim}{commandchars=\\\{\},fontsize=\fontsize{10.5}{11}\selectfont}

% box drawing characters
% <https://tex.stackexchange.com/a/333210/6444>
\usepackage{newunicodechar}
\newfontfamily{\fallbackfont}{Andale Mono}
\DeclareTextFontCommand{\textfallback}{\fallbackfont}
\newunicodechar{█}{\textfallback{█}}
\newunicodechar{└}{\textfallback{└}}
\newunicodechar{─}{\textfallback{─}}
\newunicodechar{├}{\textfallback{├}}
\newunicodechar{│}{\textfallback{│}}


% sidebar environment
\usepackage{framed,color}
\definecolor{shadecolor}{RGB}{242,242,242}
\makeatletter
\newenvironment{sidebar}{%
\medskip{}
\setlength{\fboxsep}{.8em}
 \def\at@end@of@kframe{}%
 \ifinner\ifhmode%
  \def\at@end@of@kframe{\end{minipage}}%
  \begin{minipage}{\columnwidth}%
 \fi\fi%
 \def\FrameCommand##1{\hskip\@totalleftmargin \hskip-\fboxsep
 \colorbox{shadecolor}{##1}\hskip-\fboxsep
     % There is no \\@totalrightmargin, so:
     \hskip-\linewidth \hskip-\@totalleftmargin \hskip\columnwidth}%
 \MakeFramed {\advance\hsize-\width
   \@totalleftmargin\z@ \linewidth\hsize
   \@setminipage}}%
 {\par\unskip\endMakeFramed%
 \at@end@of@kframe}
\makeatother