diff --git a/main.tex b/main.tex
index fbbdc26..eb4563b 100644
--- a/main.tex
+++ b/main.tex
@@ -2,6 +2,9 @@
 \usepackage[utf8]{inputenc}
 \usepackage[left=2cm,right=2cm,bottom=2cm, top=2cm]{geometry}
 \usepackage{amsmath}
+\usepackage{tcolorbox}
+\tcbuselibrary{theorems}
+\newtcbtheorem{definition}{Definition}{colback=red!5!white,colframe=red!75!black,fonttitle=\bfseries\large}{def}
 \usepackage{xcolor}
 \usepackage{graphicx,import}
 \usepackage{fancyhdr}
@@ -28,6 +31,7 @@
 
 \begin{document}
 
+
 \thispagestyle{empty}
 \begin{center}
     \par\noindent\rule{\textwidth}{2px}\\
@@ -41,7 +45,12 @@
 
 \newpage
 
-\section{plop}
+\section{Introduction}
+
+\begin{definition}{Artificial Intelligence}
+    plop
+\end{definition}
+
 
 
 \end{document}
diff --git a/requirements.txt b/requirements.txt
index 6e17927..680fa42 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,4 @@
 fancyhdr
 import
+tcolorbox
+environ