the following code (source) is very pretty but I would like the text quoted to occupy all the width of the page.
How can I achieve this ?
\documentclass[12pt]{article}
\usepackage[T1]{fontenc}
\usepackage{libertine}
\usepackage{graphicx}
\usepackage[svgnames]{xcolor}
\usepackage{framed}
\newcommand*\openquote{%
\makebox(25,-22){\scalebox{5}{``}}
}
\newcommand*\closequote{ %
\makebox(25,-22){\scalebox{5}{''}}
}
\colorlet{shadecolor}{lightgray}
\makeatletter
\newif\if@right
\def\shadequote{\@righttrue\shadequote@i}
\def\shadequote@i{\begin{snugshade}\begin{quote}\openquote}
\def\endshadequote{%
\if@right\hfill\fi\closequote\end{quote}\end{snugshade}}
\@namedef{shadequote*}{\@rightfalse\shadequote@i}
\@namedef{endshadequote*}{\endshadequote}
\makeatother
\begin{document}
\begin{shadequote}
Some quoted words
\end{shadequote}
\begin{shadequote*}
Some quoted words
\end{shadequote*}
\begin{shadequote}
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete fools.
\par \emph{Douglas Adams}
\end{shadequote}
\end{document}