\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}

%CÓDIGO IMÁGENES
%\begin{figure}[h!]
%    \newpage
%    \centering
%    \includegraphics[width=11cm]{i}
%    \caption{{\footnotesize{}.\emph{Fuente:}}}
%\end{figure}

%Para que LaTeX reconozca los carácteres latinos acentuados del español.
\usepackage[spanish]{babel}
\usepackage[utf8]{inputenc}

%Realizar título del documento
\usepackage{titling}

%Lorem ipsum
\usepackage{lipsum}

%Editar apariencia de títulos
\usepackage{sectsty}
\allsectionsfont{\itshape\normalsize}


\usepackage{ragged2e}

%Letrina
\usepackage{lettrine}



%Imágenes
\usepackage{graphicx}

\usepackage{csquotes}

\usepackage{setspace}
\usepackage{lipsum}
\usepackage{etoolbox}
\AtBeginEnvironment{quote}{\singlespace\vspace{-\topsep}\small}
\AtEndEnvironment{quote}{\vspace{-\topsep}\endsinglespace}

\onehalfspacing

\renewcommand{\baselinestretch}{1.25}

%Chicago citation style
\usepackage[notes]{biblatex-chicago}
\bibliography{DM.bib}






%Cambio de ancho de párrafo determinado
\newcommand\invisiblesection[1]{%
  \refstepcounter{section}%
  \addcontentsline{toc}{section}{\protect\numberline{\thesection}#1}%
  \sectionmark{#1}}

\def\changemargin#1#2{\list{}{\rightmargin#2\leftmargin#1}\item[]}
\let\endchangemargin=\endlist 

\title{Título del ensayo}
\author{Autor}
\date{Fecha}

\begin{document}



%\raggedleft{\footnotesize{\theauthor}}
\centering{\MakeUppercase{\theauthor}}
\vspace*{-0.3in}
\begin{center}
   \rule{\textwidth}{0.1mm}
\LARGE{\thetitle}\\
\vspace{1cm}

\end{center}

\begin{changemargin}{1cm}{1cm} 

\textit{\section*{\footnotesize{Resumen general}}}
\vspace*{-0.18in}




\end{changemargin}

\vspace*{2cm}
\justify


\section{{\normalsize{Introducción}}}


\section{{\normalsize{Argumentación}}}


\section{{\normalsize{Conclusiones}}}


\printbibliography



\end{document}
