如何在此代码中在章节标题中制作一个框（带阴影）

Question

\documentclass{memoir}
% Les têtes de chapitre sont définies ainsi
\makeatletter
\def\@makechapterhead#1{%
  \vspace*{20\p@}%
  {\parindent \z@ \centering
    \normalfont
    \ifnum \c@secnumdepth >\m@ne
      \if@mainmatter
        %\huge\bfseries 
        \scshape
        \@chapapp\space \thechapter
        \par\nobreak
%        \vskip 20\p@
      \fi
    \fi
    \interlinepenalty\@M
    \Huge \bfseries #1\par\nobreak
    \vskip 40\p@
  }}
\def\@schapter#1{\if@twocolumn
                   \@topnewpage[\@makeschapterhead{#1}]%
                 \else
                   \@makeschapterhead{#1}%
                   \@afterheading
                 \fi}
\def\@makeschapterhead#1{%
  \vspace*{20\p@}%
  {\parindent \z@ \centering
    \normalfont
    \scshape
    \interlinepenalty\@M
    \Huge \bfseries #1\par\nobreak
    \vskip 40\p@
  }}
\begin{document}
\chapter{Introduction}
\end{document}