```
%%%% This Beamer example was created by LianTze Lim, April 2017.
%%%% This is a VERY simple and minimalistic beamer theme,
%%%% even reminiscent of marker pens on transparencies!
%%%% It mimics the look of the "seminar" package, which
%%%% can only be used with plain TeX.
%%%% There are also some comments and example to show how
%%%% to customise various elements, e.g. the font and colours.
\documentclass[12pt]{beamer}
%% If you'd like the default font size to be even larger, use 14pt or 17pt; these are supported by Beamer.
\usepackage[english]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% These lines should usually go into a .sty file,
% but I'll leave them here so that it's easier to
% see how to customise a Beamer theme.
% Remember, the Beamer manual is your friend!!
% http://texdoc.net/pkg/beamer
%
%% So if your re-definitions have a @ somewhere, you
%% _MUST_ put a \makeatletter before these lines and then
%% \makeatother after them. This trick can only be done
%% in the preamble! BUT if you're doing these re-definitions
%% in a .sty file (so that you \usepackage it later), you
%% don't need the \makeatletter and \makeatother.
\makeatletter
%% Set the left and right margins
\setbeamersize{text margin left=1em,text margin right=1em}
%% FONTS
\setbeamerfont{title}{series=\bfseries,size=\LARGE}
\setbeamerfont{subtitle}{series=\bfseries,size=\Large}
\setbeamerfont{frametitle}{series=\bfseries,size=\small}
\setbeamerfont{block title}{series=\bfseries,size=\normalsize}
\setbeamerfont{footline}{size=\normalsize}
%% COLOURS
%% If you'd like everything to have the same colour
\usebeamercolor{structure}
\setbeamercolor{normal text}{fg=structure.fg}
%% Add a line after the frametitle
\addtobeamertemplate{frametitle}{}{\vspace*{-1ex}\rule{\textwidth}{1pt}}
%% Use circular discs as itemized list markers;
%% there's an existing option in Beamer for it so I'll use it
\setbeamertemplate{itemize items}[circle]
%% Remove default navigation symbols (We'll add the ones we need in the footline
\setbeamertemplate{navigation symbols}{}
%% And before the footline... actually we'd like to re-define
%% the footline
\setbeamertemplate{footline}{%
%% Beamer headlines and footlines are always full-paperwidth, so if you want the horizontal line to
%% not span it entirely you'll need to do a bit of arithmetic
\centering
\begin{minipage}{\dimexpr\paperwidth-\beamer@leftmargin-\beamer@rightmargin\relax}
\centering
\rule{\linewidth}{1pt}\vskip2pt
\usebeamerfont{footline}%
\usebeamercolor{footline}%
%% The frame number smack in the middle
\hfill\insertpagenumber/\inserttotalframenumber
\hfill%
%% ONLY the navigation symbols we want at the far right.
%% We use an \llap so that it takes up zero width, and doesn't throw the page number off-centre!
\llap{\insertframenavigationsymbol\insertbackfindforwardnavigationsymbol}\par
\end{minipage}\vskip2pt
}
\makeatother
%%%% END STYLE CUSTOMISATION %%%%%%%%%%%%
\title{A Really Simple, Minimalistic Beamer Theme}
\subtitle{because sometimes you just want something simple}
\author{LianTze Lim}
\institute{Overleaf}
\date{April 2017}
\begin{document}
\begin{frame}
\titlepage
\end{frame}
% Uncomment these lines for an automatically generated outline.
%\begin{frame}{Outline}
% \tableofcontents
%\end{frame}
\section{Introduction}
\begin{frame}{Introduction}
\begin{itemize}
\item Your introduction goes here!
\item Use \texttt{itemize} to organize your main points.
\end{itemize}
\vskip 1cm
\begin{block}{Examples}
Some examples of commonly used commands and features are included, to help you get started.
\end{block}
\end{frame}
\section{Some \LaTeX{} Examples}
\subsection{Tables and Figures}
\begin{frame}{Tables and Figures}
\begin{itemize}
\item Use \texttt{tabular} for basic tables --- see Table~\ref{tab:widgets}, for example.
\item You can upload a figure (JPEG, PNG or PDF) using the files menu.
\item To include it in your document, use the \texttt{includegraphics} command (see the comment below in the source code).
\end{itemize}
% Commands to include a figure:
%\begin{figure}
%\includegraphics[width=\textwidth]{your-figure's-file-name}
%\caption{\label{fig:your-figure}Caption goes here.}
%\end{figure}
\begin{table}
\centering
\begin{tabular}{l|r}
Item & Quantity \\\hline
Widgets & 42 \\
Gadgets & 13
\end{tabular}
\caption{\label{tab:widgets}An example table.}
\end{table}
\end{frame}
\subsection{Mathematics}
\begin{frame}{Readable Mathematics}
Let $X_1, X_2, \ldots, X_n$ be a sequence of independent and identically distributed random variables with $\text{E}[X_i] = \mu$ and $\text{Var}[X_i] = \sigma^2 < \infty$, and let
$$S_n = \frac{X_1 + X_2 + \cdots + X_n}{n}
= \frac{1}{n}\sum_{i}^{n} X_i$$
denote their mean. Then as $n$ approaches infinity, the random variables $\sqrt{n}(S_n - \mu)$ converge in distribution to a normal $\mathcal{N}(0, \sigma^2)$.
\end{frame}
\end{document}
```