\usepackage{titlesec}

\providecommand{\DUdocumentsubtitle}[1]{%
	\color{black}
	\EBLigatures\selectfont
	\Large
	#1\switchcolumn[1]* % Synchronise the column at this position
}

\makeatletter

\def\@maketitle{%
  \switchcolumn[1]%
  \vspace*{1cm}
  \textcolor{orange}{\fontsize{1.2cm}{2cm}\CaviarDreamsFont\selectfont \@title}
}
\makeatother


\newcommand{\periodafter}[1]{#1.}

% Titre de niveau 1
\titleformat{\section}
  {\CaviarDreamsFont\selectfont\large}
  {\thesection}
  {0em}
  {\periodafter}
  [{\color{backsidecolor}\titlerule[1pt]}]

% Titre de niveau 2
\titleformat{\subsection}
  {\large}
  {\thesubsection}
  {}
  {\textcolor{backsidecolor}}

% Titre de niveau 3
\titleformat{\subsubsection}
  {\bfseries\normalsize}
  {\thesubsubsection}
  {2em}
  {}
  {}