documentclass[a4paper, 10pt, onecolumn, openany]{memoir}

usepackage[T1]{fontenc}
usepackage[english]{babel}
usepackage[final]{microtype}
usepackage{amsmath,amssymb,mathtools} % Math
usepackage{amsmath}
usepackage{amsfonts}
usepackage{amssymb}
usepackage{makeidx}
usepackage{graphicx}
usepackage{lmodern}
usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry}
usepackage[hidelinks]{hyperref}
usepackage{textcomp}
usepackage[svgnames]{xcolor}
usepackage{amsthm}
usepackage{thmtools}


setlrmarginsandblock{0.15paperwidth}{*}{1} % Left and right margin
setulmarginsandblock{0.2paperwidth}{*}{1}  % Upper and lower margin
checkandfixthelayout


maxsecnumdepth{subsection} % Subsections (and higher) are numbered
setsecnumdepth{subsection}

makeatletter



makechapterstyle{standard}
{
  setlength{beforechapskip}{0baselineskip}
  setlength{midchapskip}{1baselineskip}
  setlength{afterchapskip}{3baselineskip}
  renewcommand{chapterheadstart}{vspace*{beforechapskip}}
  renewcommand{chapnamefont}{centeringnormalfontLarge}
  renewcommand{printchaptername}{chapnamefont @chapapp}
  renewcommand{chapternamenum}{space}
  renewcommand{chapnumfont}{normalfontLarge}
  renewcommand{printchapternum}{chapnumfont thechapter}
  renewcommand{afterchapternum}{parnobreakvskip midchapskip}
  renewcommand{printchapternonum}{vspace*{midchapskip}vspace*{5mm}}
  renewcommand{chaptitlefont}{centeringbfseriesLARGE}
  renewcommand{printchaptertitle}[1]{chaptitlefont ##1}
  renewcommand{afterchaptertitle}{parnobreakvskip afterchapskip}
}
makeatother

chapterstyle{standard}

setsecheadstyle{normalfontlargebfseries}
setsubsecheadstyle{normalfontnormalsizebfseries}
setparaheadstyle{normalfontnormalsizebfseries}
setparaindent{0pt}setafterparaskip{0pt}

makeatletter
renewcommandfps@figure{htbp}
renewcommandfps@table{htbp}
makeatother

captiondelim{space }
captionnamefont{smallbfseries}
captiontitlefont{smallnormalfont}

changecaptionwidth
captionwidth{1textwidth}


renewcommand{abstractnamefont}{normalfontsmallbfseries}
setlength{absleftindent}{0.1textwidth}
setlength{absrightindent}{absleftindent}

makepagestyle{standard}

makeatletter
makeevenfoot{standard}{}{}{}
makeoddfoot{standard}{}{}{}
makeevenhead{standard}{bfseriesthepagenormalfontqquadsmallleftmark}{}{}
makeoddhead{standard}{}{}{smallrightmarkqquadbfseriesthepage}

makeatother

makeatletter
makepsmarks{standard}{
createmark{chapter}{both}{shownumber}{@chapapp }{ quad }
createmark{section}{right}{shownumber}{}{ quad }
createplainmark{toc}{both}{contentsname}
createplainmark{lof}{both}{listfigurename}
createplainmark{lot}{both}{listtablename}
createplainmark{bib}{both}{bibname}
createplainmark{index}{both}{indexname}
createplainmark{glossary}{both}{glossaryname}
}
makeatother

makepagestyle{chap}

makeatletter
makeevenfoot{chap}{}{smallbfseriesthepage}{}
makeoddfoot{chap}{}{smallbfseriesthepage}{}
makeevenhead{chap}{}{}{}
makeoddhead{chap}{}{}{}

makeatother

nouppercaseheads
pagestyle{standard}
aliaspagestyle{chapter}{chap}


maxtocdepth{subsection} % Only parts, chapters and sections in the table of contents
settocdepth{subsection}

AtEndDocument{addtocontents{toc}{par}} % Add a par to the end of the TOC

author{author name}
title{Title}
date{June}%delete date


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


theoremstyle{definition}
newtheorem{definition}{Definition}[section]
renewcommand{thedefinition}{thesection$text{.}$arabic{definition}}


theoremstyle{theorem}
newtheorem{theorem}[definition]{Theorem}

begin{document}

frontmatter

maketitle

newpage
pagenumbering{arabic}

begin{abstract}
test
end{abstract}
clearpage

tableofcontents*
clearpage

setsecnumdepth{subsection}


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

chapter{Title of chapter}

This is a text

begin{theorem}
this is a theorem.
end{theorem}

appendix
backmatter
end{document}