-\newcommand{\@ptsize}{0}
-\DeclareOption{slide}{\@slidetrue\renewcommand{\@ptsize}{26}\@landscapetrue\@titlepagetrue}
-\DeclareOption{8pt}{\renewcommand{\@ptsize}{-2}}
-\DeclareOption{9pt}{\renewcommand{\@ptsize}{-1}}
-\DeclareOption{10pt}{\renewcommand{\@ptsize}{0}}
-\DeclareOption{11pt}{\renewcommand{\@ptsize}{1}}
-\DeclareOption{12pt}{\renewcommand{\@ptsize}{2}}
-\DeclareOption{14pt}{\renewcommand{\@ptsize}{4}}
-\DeclareOption{17pt}{\renewcommand{\@ptsize}{7}}
-\DeclareOption{20pt}{\renewcommand{\@ptsize}{10}}
-\DeclareOption{21pt}{\renewcommand{\@ptsize}{11}}
-\DeclareOption{25pt}{\renewcommand{\@ptsize}{15}}
-\DeclareOption{30pt}{\renewcommand{\@ptsize}{20}}
-\DeclareOption{36pt}{\renewcommand{\@ptsize}{26}}
-\DeclareOption{43pt}{\renewcommand{\@ptsize}{33}}
-\DeclareOption{12Q}{\renewcommand{\@ptsize}{1200}}
-\DeclareOption{14Q}{\renewcommand{\@ptsize}{1400}}
-\DeclareOption{10ptj}{\renewcommand{\@ptsize}{1001}}
-\DeclareOption{10.5ptj}{\renewcommand{\@ptsize}{1051}}
-\DeclareOption{11ptj}{\renewcommand{\@ptsize}{1101}}
-\DeclareOption{12ptj}{\renewcommand{\@ptsize}{1201}}
+\def\jsc@magscale{1}
+\DeclareOption{slide}{\@slidetrue\def\jsc@magscale{3.583}\@landscapetrue\@titlepagetrue}
+\DeclareOption{8pt} {\def\jsc@magscale{0.833}}% 1.2^(-1)
+\DeclareOption{9pt} {\def\jsc@magscale{0.913}}% 1.2^(-0.5}
+\DeclareOption{10pt}{\def\jsc@magscale{1}}
+\DeclareOption{11pt}{\def\jsc@magscale{1.095}}% 1.2^0.5
+\DeclareOption{12pt}{\def\jsc@magscale{1.200}}
+\DeclareOption{14pt}{\def\jsc@magscale{1.440}}
+\DeclareOption{17pt}{\def\jsc@magscale{1.728}}
+\DeclareOption{20pt}{\def\jsc@magscale{2}}
+\DeclareOption{21pt}{\def\jsc@magscale{2.074}}
+\DeclareOption{25pt}{\def\jsc@magscale{2.488}}
+\DeclareOption{30pt}{\def\jsc@magscale{2.986}}
+\DeclareOption{36pt}{\def\jsc@magscale{3.583}}
+\DeclareOption{43pt}{\def\jsc@magscale{4.300}}
+\DeclareOption{12Q} {\def\jsc@magscale{0.923}}% 1pt*12Q/13Q
+\DeclareOption{14Q} {\def\jsc@magscale{1.077}}% 1pt*14Q/13Q
+\DeclareOption{10ptj}{\def\jsc@magscale{1.085}}% 1pt*10bp/13Q
+\DeclareOption{10.5ptj}{\def\jsc@magscale{1.139}}
+\DeclareOption{11ptj}{\def\jsc@magscale{1.194}}
+\DeclareOption{12ptj}{\def\jsc@magscale{1.302}}
+\newif\if@ltjs@mag@xreal
+\@ltjs@mag@xrealtrue
+\DeclareOption{nomag*}{\@ltjs@mag@xrealtrue}
+\DeclareOption{nomag}{\@ltjs@mag@xrealfalse}
+\DeclareOption{noxreal}{%
+ \ClassWarningNoLine{\jsc@clsname}{%
+ The class option `noxreal' is obsolete. \MessageBreak
+ Please use the `nomag' option instead}%
+ \@ltjs@mag@xrealfalse}
+\DeclareOption{real}{%
+ \ClassWarningNoLine{\jsc@clsname}{%
+ The class option `real' is obsolete. \MessageBreak
+ Please use the `nomag' option instead}%
+ \@ltjs@mag@xrealfalse}
+\DeclareOption{usemag}{%
+ \ClassWarningNoLine{\jsc@clsname}{%
+ This \jsc@clsname\space cls does not support `usemag'\MessageBreak
+option, since LuaTeX does not support \string\mag\MessageBreak in pdf output}%
+ \@ltjs@mag@xrealtrue}
+