Use unicode-math.

Use `mathspec` with only XeLaTeX on request.

default.latex

@@ -21,11 +21,17 @@ $if(euro)$
   \usepackage{eurosym}
 $endif$
 \else % if luatex or xelatex
+$if(mathspec)$
   \ifxetex
     \usepackage{mathspec}
   \else
     \usepackage{fontspec}
+    \usepackage{unicode-math}
   \fi
+$else$
+  \usepackage{fontspec}
+  \usepackage{unicode-math}
+$endif$
   \defaultfontfeatures{Ligatures=TeX,Scale=MatchLowercase}
 $for(fontfamilies)$
   \newfontfamily{$fontfamilies.name$}[$fontfamilies.options$]{$fontfamilies.font$}
@@ -43,7 +49,14 @@ $if(monofont)$
     \setmonofont[Mapping=tex-ansi$if(monofontoptions)$,$for(monofontoptions)$$monofontoptions$$sep$,$endfor$$endif$]{$monofont$}
 $endif$
 $if(mathfont)$
+$if(mathspec)$
+  \ifxetex
     \setmathfont(Digits,Latin,Greek)[$for(mathfontoptions)$$mathfontoptions$$sep$,$endfor$]{$mathfont$}
+  \else
+    \setmathfont[$for(mathfontoptions)$$mathfontoptions$$sep$,$endfor$]{$mathfont$}
+  \fi
+$else$
+  \setmathfont[$for(mathfontoptions)$$mathfontoptions$$sep$,$endfor$]{$mathfont$}
 $endif$
 $if(CJKmainfont)$
     \usepackage{xeCJK}