--- a/slides/slides01.tex	Wed Sep 02 23:34:19 2020 +0100
+++ b/slides/slides01.tex	Mon Sep 07 12:18:07 2020 +0100
@@ -5,6 +5,11 @@
 \usepackage{../langs}
 \usepackage{../data}
 
+\usepackage{tcolorbox}
+\newtcolorbox{mybox}{colback=red!5!white,colframe=red!75!black}
+\newtcolorbox{mybox2}[1]{colback=red!5!white,colframe=red!75!black,fonttitle=\bfseries,title=#1}
+\newtcolorbox{mybox3}[1]{colback=Cyan!5!white,colframe=Cyan!75!black,fonttitle=\bfseries,title=#1}
+
 
 
 \hfuzz=220pt 
@@ -26,8 +31,24 @@
 
 \begin{document}
 
+\begin{frame}[t]
+\begin{mybox}
+A physical explanation the \emph{dynamic matrix}\\
+lots of text
+\end{mybox}
 
 
+\begin{mybox2}{Test}
+A physical explanation the \emph{dynamic matrix}\\
+lots of text
+\end{mybox2}
+
+\begin{mybox3}{Test}
+A physical explanation the \emph{dynamic matrix}\\
+lots of text
+\end{mybox3}
+\end{frame}
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \begin{frame}[t]
 \frametitle{%