acl.sty

\usepackage{etoolbox}

% Adjust space before and after section titles
\patchcmd{\section}
  {\vspace{-3.5ex plus -1ex minus -.2ex}}
  {\vspace{-3.5ex plus -1ex minus -.2ex} \vspace{1em}}
  {}{}

\patchcmd{\subsection}
  {\vspace{-3.25ex plus -1ex minus -.2ex}}
  {\vspace{-3.25ex plus -1ex minus -.2ex} \vspace{0.75em}}
  {}{}

\patchcmd{\subsubsection}
  {\vspace{-3ex plus -1ex minus -.2ex}}
  {\vspace{-3ex plus -1ex minus -.2ex} \vspace{0.5em}}
  {}{}

\renewcommand{\tiny}{\fontsize{5}{6}\selectfont}
\renewcommand{\scriptsize}{\fontsize{6}{7}\selectfont}
\renewcommand{\footnotesize}{\fontsize{7}{8}\selectfont}
\renewcommand{\small}{\fontsize{8}{9.5}\selectfont}
\renewcommand{\normalsize}{\fontsize{9}{11}\selectfont}
\renewcommand{\large}{\fontsize{10}{12}\selectfont}
\renewcommand{\Large}{\fontsize{12}{14}\selectfont}
\renewcommand{\LARGE}{\fontsize{14}{16}\selectfont}
\renewcommand{\huge}{\fontsize{16}{18}\selectfont}
\renewcommand{\Huge}{\fontsize{18}{20}\selectfont}