\usepackage{titlesec}


\providecommand*{\DUdocumentsubtitle}[1]{{\EBLigatures\selectfont\em\LARGE\begin{flushright}#1\end{flushright}}}

\makeatletter

%\def\@subtitle{\relax}
\newcommand{\subtitle}[1]{\gdef\@subtitle{#1}}

\def\@maketitle{%
  \begin{tcolorbox}[colback=sidecolor, sharp corners]
  \begin{center}
    \vspace*{1cm}
    \textcolor{white}{\fontsize{1.2cm}{2cm}\CaviarDreamsFont\selectfont \@title}
  \end{center}
  \vspace*{1cm}
  \end{tcolorbox}
}
\makeatother


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

% Titre de niveau 1
\titleformat{\section}
  {\CaviarDreamsFont\selectfont\Large\centering}
  {\thesection}
  {0em}
  {\vspace{1cm}}
  []

% Titre de niveau 2
\titleformat{\subsection}
  {\large}
  {\thesubsection}
  {}
  {\textcolor{black!69}}

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