diff --git a/src/environments/thmstyle/.latexmkrc b/src/environments/thmstyle/.latexmkrc
new file mode 100644
index 0000000..d4f5fa8
--- /dev/null
+++ b/src/environments/thmstyle/.latexmkrc
@@ -0,0 +1,6 @@
+@default_files = ("thmstyle.dtx");
+$makeindex = "makeindex -s gind.ist %O -o %D %S";
+$clean_ext .= ' glo';
+$clean_ext .= ' hd';
+$clean_full_ext .= ' sty';
+$emulate_aux = 1;
diff --git a/src/environments/thmstyle/Makefile b/src/environments/thmstyle/Makefile
new file mode 100644
index 0000000..4e0d5d2
--- /dev/null
+++ b/src/environments/thmstyle/Makefile
@@ -0,0 +1,10 @@
+pdf:
+	latexmk 
+
+full:
+	latexmk -gg 
+
+clean:
+	latexmk -C 
+
+.PHONY: clean
diff --git a/src/environments/thmstyle/thmstyle.dtx b/src/environments/thmstyle/thmstyle.dtx
new file mode 100644
index 0000000..bf49cff
--- /dev/null
+++ b/src/environments/thmstyle/thmstyle.dtx
@@ -0,0 +1,328 @@
+% \iffalse meta-comment
+%<*internal>
+\begingroup
+\input docstrip.tex
+\keepsilent
+\usedir{tex/latex/mkessler/thmstyle}
+\askforoverwritefalse
+\generate{\file{thmstyle.sty}{\from{thmstyle.dtx}{package}}}
+\def\tmpa{plain}
+\ifx\tmpa\fmtname\endgroup\expandafter\bye\fi
+\endgroup
+%</internal>
+%
+%% File: thmstyle.dtx
+%
+% Copyright (C) 2022 Maximilian Keßler
+%
+% It may be distributed and/or modified under the conditions of the
+% LaTeX Project Public License (LPPL), either version 1.3c of this
+% license or (at your option) any later version.  The latest version
+% of this license is in the file
+%
+%    https://www.latex-project.org/lppl.txt
+%
+% -----------------------------------------------------------------------
+%<package>\ProvidesExplPackage{thmstyle}{2022/01/17}{0.0.1}{Grouped theorems.}
+%
+%<*driver>
+\documentclass[full,kernel]{l3doc}
+\begin{document}
+  \DocInput{\jobname.dtx}
+\end{document}
+%</driver>
+% \fi
+%
+% \title{^^A
+%   The \pkg{thmstyle} package^^A
+% }
+%
+% \author{^^A
+%      Maximilian Ke\ss ler
+% }
+%
+% \date{Released 2022-01-12}
+%
+% \maketitle
+%
+% \begin{documentation}
+% 
+%
+%
+% \end{documentation}
+% 
+% 
+% \begin{implementation}
+% 
+% \section{\pkg{thmstyle} implementation}
+%
+% 
+%    \begin{macrocode}
+%<*package>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<@@=thmstyle>
+%    \end{macrocode}
+%
+%
+% 
+% 
+% 
+% 
+% 
+% 
+%
+%
+% \subsection{Dependencies}
+% 
+% 
+% 
+%    \begin{macrocode}
+\RequirePackage{amsthm}
+\RequirePackage{thmtools}
+\RequirePackage{mdframed}
+\RequirePackage{xcolor}
+\RequirePackage{l3keys2e}
+%    \end{macrocode}
+% 
+% 
+% \subsection{Initialization}
+% \begin{variable}{\g_@@_default_styles_bool}
+%
+%  Indicates whether the package will provide default styles.
+%
+%    \begin{macrocode}
+\bool_new:N \g_@@_default_styles_bool
+%    \end{macrocode}
+% \end{variable}
+% 
+%
+% 
+% 
+% \begin{variable}{gold}
+% New color
+%    \begin{macrocode}
+\definecolor{gold}{RGB}{218,165,32}
+%    \end{macrocode}
+% \end{variable}
+%
+% 
+% 
+% 
+% 
+% 
+% 
+% \subsection{Package options}
+% 
+% 
+%
+%    \begin{macrocode}
+\keys_define:nn { thmstyle }
+  {
+    default styles   .set_bool:N  = \g_@@_default_styles_bool,
+    default styles   .default:n   = { false },
+  }
+%    \end{macrocode}
+% 
+%
+%    \begin{macrocode}
+\ProcessKeyOptions { thmstyle }
+%    \end{macrocode}
+% 
+% 
+% 
+% 
+% \subsection{Private Wrappers}
+%
+%
+% \begin{macro}{\@@_mdframed_define_style:nn, \@@_mdframed_define_style:nx}
+%    \begin{syntax}
+%       \cs{@@_mdframed_define_style:nn}\marg{key=value list}\marg{style}
+%    \end{syntax}
+%		 
+%     
+%
+%    \begin{macrocode}
+\cs_new:Npn \@@_mdframed_define_style:nn #1 #2 
+  {
+    \mdfdefinestyle{#2}{#1}
+  }
+%    \end{macrocode}
+% \end{macro}
+% 
+% 
+% \begin{macro}{\@@_thmtools_declare_style:nn, \@@_thmtools_declare_style:xx}
+%    \begin{syntax}
+%       \cs{@@_thmtools_declare_style:nn}\marg{key=value list}\marg{style}
+%    \end{syntax}
+%		 
+%     
+%
+%    \begin{macrocode}
+\cs_new:Npn \@@_thmtools_declare_style:nn #1 #2
+  {
+    \declaretheoremstyle[#1]{#2}
+  }
+\cs_generate_variant:Nn \@@_thmtools_declare_style:nn { x x }
+%    \end{macrocode}
+% \end{macro}
+% 
+% 
+% \subsection{Generation of styles}
+% 
+% \begin{macro}{\thmstyle_declare_mdf_style:nnn}
+%    \begin{syntax}
+%       \cs{thmstyle_declare_mdf_style:nnn}\marg{style}\marg{margin color}\marg{background color}
+%    \end{syntax}
+%     
+%
+%    \begin{macrocode}
+\cs_new:Npn \thmstyle_declare_mdf_style:nnn #1 #2 #3 
+  {
+    \@@_mdframed_define_style:nn
+      {
+        linecolor       = #2,
+        linewidth       = 2pt,
+        leftmargin      = 0pt,
+        rightmargin     = 0pt,
+        rightline       = false,
+        topline         = false,
+        bottomline      = false,
+        backgroundcolor = #3
+      }
+      {
+        #1
+      }
+  }
+\cs_generate_variant:Nn \thmstyle_declare_mdf_style:nnn { x n x }
+%    \end{macrocode}
+% \end{macro}
+% 
+% 
+% 
+%
+% \begin{macro}{\DeclareFancyMdfStyle}
+%    \begin{syntax}
+%      \cs{DeclareFancyMdfStyle}\oarg{background color}\marg{line color}\oarg{style}
+%    \end{syntax}
+%		 
+%     
+%
+%    \begin{macrocode}
+\NewDocumentCommand { \DeclareFancyMdfStyle } { o m o }
+  {
+    \thmstyle_declare_mdf_style:xnx
+      {
+        \IfValueTF { #3 }
+          {
+            #3
+          }
+          {
+            md #2 margin
+            \IfValueT { #1 }
+              {
+                and #1 fill
+              }
+          }
+      }
+      {
+        #2
+      }
+      {
+        \IfValueTF { #1 }
+          {
+            #1
+          }
+          {
+            white
+          }
+      }
+  }
+%    \end{macrocode}
+% \end{macro}
+% 
+% 
+% 
+% 
+% 
+% 
+% 
+% 
+%
+% \begin{macro}{\DeclareFancyThmStyle}
+%    \begin{syntax}
+%       \cs{DeclareFancyThmStyle}\oarg{background color}\marg{line color}\oarg{style}
+%    \end{syntax}
+%		 
+%     
+%
+%    \begin{macrocode}
+\NewDocumentCommand { \DeclareFancyThmStyle } { o m o }
+  {
+    \DeclareFancyMdfStyle { #1 } { #2 }
+    \@@_thmtools_declare_style:xx
+      {
+        mdframed      = 
+          {
+            style = md #2 margin \IfValueT { #1 } { and #1 fill }
+          },
+        postheadspace = { 0.3em },
+        notefont      = \mdseries,
+      }
+      {
+        \IfValueTF { #3 }
+          { #3 }
+          {
+            thm #2 margin
+            \IfBooleanT { #1 }
+              {
+                and #1 fill
+              }
+          }
+      }
+  }
+%    \end{macrocode}
+% \end{macro}
+% 
+% 
+% \subsection{Default styles}
+%
+% 
+% Here, we provide the default styles:
+%
+% 
+%    \begin{macrocode}
+\bool_if:NT \g_@@_default_styles_bool
+  {
+      \DeclareFancyThmStyle[red!8]{red}[thmredmarginandfill]
+      \DeclareFancyThmStyle[orange!10]{orange}[thmorangemarginandfill]
+      \DeclareFancyThmStyle[blue!7]{blue}[thmbluemarginandfill]
+      \DeclareFancyThmStyle{green!70!black}[thmgreenmargin]
+      \DeclareFancyThmStyle{gold}[thmgoldmargin]
+      \DeclareFancyThmStyle{yellow!80!orange}[thmyellowmargin]
+      \DeclareFancyThmStyle{gray}[thmgraymargin]
+      \DeclareFancyThmStyle[violet!7]{violet}[thmvioletmarginandfill]
+      \DeclareFancyThmStyle{violet}[thmvioletmargin]
+      \DeclareFancyThmStyle[blue!7]{red}[thmredmarginbluefill]
+      \DeclareFancyThmStyle{red}[thmredmargin]
+      \DeclareFancyThmStyle[blue!7]{orange}[thmorangemarginbluefill]
+      \DeclareFancyThmStyle[violet!20!gray!20]{black}[thmblackmarginandfill]
+      \DeclareFancyThmStyle{black}[thmblackmargin]
+  }
+%    \end{macrocode}
+% 
+% 
+% 
+% 
+% 
+%    \begin{macrocode}
+%</package>
+%    \end{macrocode}
+%
+%   \end{implementation}
+% 
+% 
+% 
+% \newpage
+% \PrintIndex