\documentclass[a4paper]{article}
\usepackage{graphicx, hyperref, xcolor, gensymb, amssymb, mathtools, wrapfig, mathtools, microtype, lastpage, caption, titlesec, paracol, longtable, booktabs, cancel}
\usepackage[T2A, T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[russian, ukrainian]{babel}
\hypersetup{
    colorlinks,
    linkcolor={blue!20!black},
    citecolor={blue!50!black},
    urlcolor={blue!80!black}
}

\usepackage[left = 25mm, right = 10mm, top=20mm, bottom=20mm, bindingoffset=0cm]{geometry}

% КОМАНДИ

\newcommand{\fnt}{
\fontshape{n}
\fontsize{14pt} {19pt}
\linespread{0.8}
\selectfont
} % нормативний шрифт
\newcommand{\capfnt}{
    \fnt
} % норматичний шрифт для підписів (тимчасово співпадає зі звичайним шрифтом)

\newcommand{\tb}{
    \hspace*{10mm}
} % відступ у 5 символів "x" відповідно до ДСТУ
\newcommand{\tbln}{
    \newline 
    \tb
} % те ж саме, але з переносом рядка
\newcommand{\tbsp}{
    \vspace*{1ex}
    \tbln
} % те ж саме, але з додатковим відступом між рядками

% бібліографія
\usepackage[square,sort,comma,numbers]{natbib}
\renewcommand{\bibsection}{}
\usepackage{totcount}
\newtotcounter{citnum} 
% лічильник цитувань
\def\oldbibitem{} \let\oldbibitem=\bibitem
\def\bibitem{\stepcounter{citnum}\oldbibitem}

% лічильник зображень
\newtotcounter{graphnum}
\def\oldincludegraphics{} \let\oldincludegraphics=\includegraphics
\def\includegraphics{\stepcounter{graphnum}\oldincludegraphics}

% лічильник таблиць (НЕАВТОМАТИЧНИЙ!!!)
\newtotcounter{tabnum}

% лічильник додатків (НЕАВТОМАТИЧНИЙ!!!)
\newtotcounter{dodnum}

% нумерація сторінок
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhf{}
\renewcommand{\headrulewidth}{0pt}
\setlength{\headheight}{15.3pt}
\fancyhead[R]{\fnt \thepage}

% виноски
\renewcommand{\thefootnote}{\large\arabic{footnote})~}
\renewcommand{\footnoterule}{\rule{20mm}{0.4pt} \vspace*{0.5ex}}
% \newcommand{\vyn}[2]{
%     \footnote[#1]{\large #2}
% } % створити виноску

\let\oldFootnote\footnote
\renewcommand{\footnote}[1]{
    \oldFootnote{\large #1}
} % перегрузка виноски

\providecommand{\tightlist}{%
  \setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}

% підписи малюнків/таблиць
\captionsetup[figure]{name={\fnt Рисунок~},labelsep=period}
\captionsetup[table]{name={\fnt Таблиця~},labelsep=period}

% markdown strikeouts
\usepackage{soul}

% codeblocks
\usepackage{minted}

% enumeration
\usepackage[shortlabels]{enumitem}

% scaleable font (whatever that means)
\usepackage[normalem]{ulem}

\titleformat*{\section}{\fnt\LARGE\bfseries}
\titleformat*{\subsection}{\fnt\Large\bfseries}
\titleformat*{\subsubsection}{\fnt\Large}

% bra and ket from QM
\usepackage{braket}

\begin{document}
\thispagestyle{empty} % [A]:for cropping
% ------------
% source: https://tex.stackexchange.com/questions/173651/need-help-to-create-such-a-beautiful-title-page
\begingroup
\centering
\obeylines
\topskip 0pt % source: https://tex.stackexchange.com/questions/2326/vertically-center-text-on-a-page
\vspace*{\fill}
\textbf{
\LARGE 
\LARGE 
\vspace{100pt}
\LARGE 
\Large 
\Large 
\Large 
\huge 
\vspace{50pt}
\large 
\large 
\large 
\large 
\vspace*{\fill}
\hspace{\fill}\large  \rule{20mm}{0.4pt}
\vspace{10pt}
}
\endgroup
% ------------
\newpage
\tableofcontents

\newpage
\fnt
This test is dedicated to attempts of parser deception, i.e. usage of special symbols in wrong places to see if parser recognizes them as control symbols. There we go:
\section{Page dividers}

\tb Page dividers are represented by ------
\tbln If the line above has dashes     ^^^^^^ here, it probably works alright.
\tbln Here's a genuine divider
\clearpage

\tb Fun fact: there can be a paragraph right after it!
\clearpage
 Some text, cause why not
\tbln But this \textbf{DOES} look cursed, don't do it.
\section{Headers}

\tb Headers are most recognizable by '\#'-symbol. For it to actually represent a header, it needs to at the beginning of the line and there should be no more than 6 of them. \textbf{ANYTHING} up to the end of line will be included into a header, then.
\tbln Example:
\textbf{This is a long, yet formally correct header. You can add $equations$ and *formatting* here, but I provide no guarantees as of the way these would display in final document.}

\tb Here's an example of incorrect header:
\tbln \#\#\#\#\#\# This header is considered incorrect for this application, and will be parsed as regular paragraph instead
\tbln Another example of incorrect header, featuring 7 hash-symbols:
\tbln \#\#\#\#\#\#\# This will be parsed as a regular paragraph
\section{Equations}

\tb There are two types of equations in markdown/latex: inline mathmode and display mathmode
\tbln Both of them are defined by $-symbols. However, they must be paired to actually represent these. Here are examples:
\tbln Inline: $y = x ^ 2$
\tbln Display:
\begin{equation}
y = x ^ 2
\end{equation}

\tb Note that display mathmode should ALWAYS start from a new line for this application.
\tbln Basically, there's not much to deceive for: you can do that:
\tbln $
\tbln $
\tbln (the above should not be mathmode), and that's it, basically :sad:
\section{Table}

\tb Tables are defined by |-symbol. But the actual table will happen only if they are the first thing on the line.
\tbln Due to current implementation, there's no cure apart from display mathmode and code:
\tbln (this should be display mathmode):
\begin{equation}
|x|
\end{equation}

\tb (this should be a code block):
\begin{minted}[linenos, mathescape, autogobble, breaklines]{bash}
head /dev/random
| cat
\end{minted}


\section{Figure}

\tb Figure is defined by a ![[ sequence at a start of the line. Same points should be uphold here:
\begin{equation}
![[
\end{equation}

\begin{minted}[linenos, mathescape, autogobble, breaklines]{text}
![[
\end{minted}


\section{References}

\tb These start with []
\subsection{Hyperrefs}

\tb These are followed by parentheses (). Nothing is allowed between them, thus
\tbln Here's a correct href: \href{https://youtu.be/rickroll_link_lol}{my gh page}
\tbln Here are incorrect refs:
\tbln [my gh page] (https://youtu.be/rickroll\textit{link}lol)
\tbln [my gh page]
\tbln (https://youtu.be/rickroll\textit{link}lol)
\subsection{Footnote refs}

\tb These are started by [^.
\tbln Here are correct footnote refs: \footnotemark[1], \footnotemark[2]
\tbln Here are incorrect ones: [^1, ^1],
\tbln [^
\tbln 1
\tbln ]
\tbln So on
\subsection{Object refs}

\tb These refer to objects like figures, tables and equations.
\tbln Started by [@.
\tbln Here's a correct ref: \ref{fig:experiment_schema}
\tbln Here's are bad ones: [@ fig:1, @  source3],
\tbln [@
\tbln eq2
\tbln ]
\tbln \textbf{NOTE}: despite object types being prepended with 'eq', 'fig' or 'tab' in refs, you \textit{can} use regular latex to define your custom refs. In fact, LaTeX doesn't care about all of these at all; I'm doing these transformations just for my own comfort, as I've been doing this manually.
\section{Formatting}

\tb This object's type is deprecated and will be removed soon.
\tbln It starts and ends with
\begin{itemize}
\item * or \_
\item ** or \_\_
\item ~~
\end{itemize}
\tb \textbf{WARN}: As of now, these \textit{might} cause cause massive problems if encountered at the start of the line.
\tbln Basically, parsers for these tokens attempt parse everything up until they find a closing token. But if they are inserted in a middle of the text, then it's ok - they will be limited by current paragraph, and (most likely) will find no match inside it, if their use was unintended.
\section{Footnote content}

\tb These start with '\footnotemark[3]:' and proceed to the end of line.
\tbln Example of valid content:
\tbln Example of invalid content:
\tbln [^source2: This is invalid content\footnotemark[4]\footnotetext[4]{Explanation of source2.} : This is invalid content \footnotemark[4]: This is invalid content
\tbln They also must start at the beginning of the line. If fact, this: \footnotemark[4]: Some content
\tbln Is expected to be a footnote ref with a colon.
\section{Code blocks}

\tb There are two fundamental types of code blocks: normal code block and \textbf{Ayano} code block.
\subsection{Normal code block}

\tb These start and end with '```' on a newline. There can be \textbf{practically anything} inside. Example:
\begin{minted}[linenos, mathescape, autogobble, breaklines]{java}
int x = 2;
int y = 4;
int[] arr = new int[2];
arr[0] = x;
arr[1] = 4;
\end{minted}


\tb There can be anything after code block had closed:
\begin{minted}[linenos, mathescape, autogobble, breaklines]{lua(Idk why vscode detects this block closing as a valid lua syntax)}
local x = 'matt'
local y = 'y'
local z = x .. y -- matty!!
\end{minted}

 Here's some text that's ok to be here
\tbln There can't be any spaces before delimiting ```s:
\tbln ```python
\tbln \# This here is not really a python block
\tbln x = 2
\tbln print(x)
\tbln ```
\subsection{Ayano code block}

\tb \textit{because Ayano loves Kyoko}
\tbln This object looks and behaves just like normal code block, but is only limited to \textit{python} language, can have spacial arguments in a language line, may leave something behind in the document. For example:
\tbln This Ayano block will leave plain "2" behind it:2
\tbln Akin to normal blocks, it's ok to leave something trailing:
\begin{minted}[linenos, mathescape, autogobble, breaklines]{ayano}
2
\end{minted}

 This text is ok to be here
\tbln And these are invalid Ayano blocks:
\begin{minted}[linenos, mathescape, autogobble, breaklines]{ayano}
2
\end{minted}


\tb ```ayano
\tbln 2
\tbln ```

\end{document}