\usepackage{tcolorbox}
\usepackage{etoolbox}

% paragraph indentation
\usepackage{parskip}
\newcommand{\nl}{\newline\indent}
%\setlength{\parfill}{0pt}
\setlength{\parindent}{15pt}

% to add subtitle to \maketitle
\makeatletter
\providecommand{\subtitle}[1]{
  \apptocmd{\@title}{\par {\large #1 \par}}{}{}
}
\makeatother

% for png/pdf inclusion (pdfpages: full-page)
\usepackage{graphicx}
\graphicspath{{img/}}
\usepackage{pdfpages}

\usepackage{lmodern}

% for Japanese chars
\usepackage{xeCJK}
\setCJKmainfont[BoldFont=STHeiti,ItalicFont=STKaiti]{STSong}

% for itemization, other symbol
\renewcommand{\labelitemi}{$\circ$}
% labelitemii, iii, iv, ... kan ook

% for index
\usepackage{imakeidx}
\makeindex[title=Appendix,columns=2,intoc,options= -s indexstyle.ist]

\newcommand{\starbreak}{%
    \fancybreak{* * *}%
}

\DeclareRobustCommand{\cs}[1]{\texttt{\char`\\#1}}
\newlength{\tpheight}\setlength{\tpheight}{0.9\textheight}
\newlength{\txtheight}\setlength{\txtheight}{0.9\tpheight}
\newlength{\tpwidth}\setlength{\tpwidth}{0.9\textwidth}
\newlength{\txtwidth}\setlength{\txtwidth}{0.9\tpwidth}
\newlength{\drop}

% hoofdstuk header style ( - 1 -, naam HF)
\chapterstyle{dash}\renewcommand*{\chaptitlefont}{\normalfont\itshape\LARGE}
\setlength{\beforechapskip}{2\onelineskip}
\setsecheadstyle{\normalfont\Large\raggedright}