nusletter.sty

\ProvidesPackage{nusletter}[NUS letterhead]
% Michael Yoshitaka Erlewine (mitcho), mitcho@nus.edu.sg
% Dedicated to the public domain, 2018--2023

\RequirePackage{kvoptions,etoolbox}
\SetupKeyvalOptions{prefix=nusletter@}
\DeclareBoolOption{blue}
\DeclareBoolOption{black}
\ProcessKeyvalOptions*

% font for 
\RequirePackage{sourcesanspro}
% just set \sfdefault locally

\RequirePackage{afterpage}
\RequirePackage{geometry}
\geometry{margin=25mm}

% positioning
\RequirePackage{calc}
\RequirePackage[absolute]{textpos}

% graphics
\RequirePackage{graphicx}
\RequirePackage{xcolor}
\definecolor{nusblue}{HTML}{163C78} % Pantone 294U
\definecolor{nusorange}{HTML}{f07d08} % Pantone 152U

\AtBeginDocument{

	% color block
	\notbool{nusletter@black}{% only if not black
		\begin{textblock*}{\paperwidth}(0mm,0mm)
		\ifbool{nusletter@blue}{%
			\noindent\textcolor{nusblue}{\rule{\paperwidth}{25mm}}%
		}{%
			\noindent\textcolor{nusorange}{\rule{\paperwidth}{25mm}}%
		}
		\end{textblock*}
	}{}

	% logo
	\begin{textblock*}{33mm}(\paperwidth - 33mm - 10mm,6mm)
	\ifbool{nusletter@blue}{%
		\noindent\includegraphics[width=33mm]{logo-blue-trim}%
	}{%
		\ifbool{nusletter@black}{%
		\noindent\includegraphics[width=33mm]{logo-black-trim}%
		}{
		\noindent\includegraphics[width=33mm]{logo-orange-trim}%
		}
	}	
	\end{textblock*}

	% first page geometry
	\enlargethispage{-10mm}
	\vspace*{5mm}
}

\newcommand{\nushead}[1]{
	\begin{textblock*}{\paperwidth - 50mm}(25mm,6mm)
	\begingroup
		\notbool{nusletter@black}{\color{white}}{}%
		\ifxetex%
			\sourcesanspro%
		\else%
			\renewcommand{\sfdefault}{SourceSansPro-LF}\sffamily%
		\fi%
		\parindent=0pt
		#1
		\endgroup
	\end{textblock*}
}

\newcommand{\nusfoot}[1]{
	\begin{textblock*}{\paperwidth - 50mm}(25mm, \paperheight - 25mm)
	\begingroup
		\notbool{nusletter@black}{\color{nusblue}}{}\footnotesize%
		\ifxetex%
			\sourcesanspro%
		\else%
			\renewcommand{\sfdefault}{SourceSansPro-LF}\sffamily%
		\fi%
		\parindent=0pt
		#1
		\endgroup
	\end{textblock*}
}