\RequirePackage{rotis}
\RequirePackage{memoir-subtitle}

\pretitle{\begin{center}\LARGE\rmfamily}
\presubtitle{\vspace{-1em}\begin{center}\Large\rmfamily}
\preauthor{\begin{center}\large\rmfamily \lineskip .5em \begin{tabular}[t]{c}}
\predate{\begin{center}\large\rmfamily}

\renewcommand{\abstractnamefont}{\normalfont\rmfamily\small\bfseries}

\makechapterstyle{rotis-fonts}{%
  \renewcommand{\partnamefont}{\rmfamily\huge\bfseries}
  \renewcommand{\parttitlefont}{\partnamefont}
  \renewcommand{\partnumfont}{\partnamefont}

  \renewcommand{\chapnamefont}{\rmfamily\huge}
  \renewcommand{\chaptitlefont}{\chapnamefont}
  \renewcommand{\chapnumfont}{\chapnamefont}

  \setsecheadstyle{\Large\rmfamily\bfseries\raggedright}
  \setsubsecheadstyle{\large\rmfamily\bfseries\raggedright}
  \setsubsubsecheadstyle{\normalsize\rmfamily\bfseries\raggedright}
  \setparaheadstyle{\normalsize\rmfamily\bfseries\raggedright}
  \setsubparaheadstyle{\normalsize\rmfamily\raggedright}
}

\makechapterstyle{article-rotis}{%
  \chapterstyle{rotis-fonts}
  \chapterstyle{article}
  \renewcommand{\chaptitlefont}{\normalfont\rmfamily\Large\bfseries}
  \renewcommand{\chapnumfont}{\normalfont\rmfamily\Large\bfseries}
}