% load packages
\usepackage{geometry}
\usepackage{xcolor}
\usepackage{eso-pic}
\usepackage{fancyhdr}
\usepackage{sectsty}
\usepackage{fontspec}
\usepackage{titlesec}

%% Set page size with a wider right margin
\geometry{a4paper, total={170mm,257mm}, left=20mm, top=20mm, bottom=20mm, right=50mm}

%% Let's define some colours
\definecolor{light}{HTML}{ECF1EC}
\definecolor{highlight}{HTML}{800080}
\definecolor{dark}{HTML}{330033}

\AddToShipoutPicture{%
    % Add right sidebar
    \AtPageLowerLeft{%
        \put(\LenToUnit{\dimexpr\paperwidth-3cm},0){%
            \color{light}\rule{3cm}{\paperheight}%
        }%
    }%
    % Add logo
    \AtPageLowerLeft{%
        \put(\LenToUnit{\dimexpr\paperwidth-2.25cm},\LenToUnit{27.2cm}){%
            \includegraphics[width=1.5cm,bb=0 0 100 100]{_extensions/drwater/dwen/rceeslogo.svg}
        }%
    }%
}

%% Style the page number
\fancypagestyle{mystyle}{
  \fancyhf{}
  \renewcommand\headrulewidth{0pt}
  \fancyfoot[R]{\thepage}
  \fancyfootoffset{3.5cm}
}
\setlength{\footskip}{20pt}

%% style the chapter/section fonts
\chapterfont{\color{dark}\fontsize{20}{16.8}\selectfont}
\sectionfont{\color{dark}\fontsize{20}{16.8}\selectfont}
\subsectionfont{\color{dark}\fontsize{14}{16.8}\selectfont}
\titleformat{\subsection}
  {\sffamily\Large\bfseries}{\thesection}{1em}{}[{\titlerule[0.8pt]}]
  
% left align title
\makeatletter
\renewcommand{\maketitle}{\bgroup\setlength{\parindent}{0pt}
\begin{flushleft}
  {\sffamily\huge\textbf{\MakeUppercase{\@title}}} \vspace{0.3cm} \newline
  {\Large {\@subtitle}} \newline
  \@author
\end{flushleft}\egroup
}
\makeatother