Github buttons are using compact style!

src/themes/github/elements/button.variables

@@ -2,10 +2,6 @@
    Button Variables
 --------------------*/
 
-/* These are also set in site.variables, however allows use of buttons standalone */
-@emSize: 13px;
-@pageFont: Helvetica Neue, Helvetica, Arial, sans-serif;
-
 /* Text Style */
 @textTransform: none;
 @fontWeight: bold;
@@ -21,6 +17,7 @@
 @iconOpacity: 1;
 @iconHeight: 13px;
 @iconDistance: @relative4px;
+@lineHeight: 1.53184em;
 
 @verticalPadding: @relative6px;
 @horizontalPadding: @relative10px;
@@ -77,4 +74,14 @@
 @secondaryColor: @black;
 
 @positiveColor: #84D767;
-@positiveColorHover: #5DC438;
+@positiveColorHover: #5DC438;
+
+/* Sizes */
+@mini: 10px;
+@tiny: 11px;
+@small: 12px;
+@medium: 13px;
+@large: 15px;
+@big: 16px;
+@huge: 18px;
+@massive: 24px;

src/themes/github/globals/site.variables

@@ -40,4 +40,36 @@
 
 @infoTextColor: #4E575B;
 @warningTextColor: #613A00;
-@errorTextColor: #991111;
+@errorTextColor: #991111;
+
+
+/* Derived EM */
+@1px          : unit( (1 / @emSize), rem);
+@2px          : unit( (2 / @emSize), rem);
+@3px          : unit( (3 / @emSize), rem);
+@4px          : unit( (4 / @emSize), rem);
+@5px          : unit( (5 / @emSize), rem);
+@6px          : unit( (6 / @emSize), rem);
+@7px          : unit( (7 / @emSize), rem);
+@8px          : unit( (8 / @emSize), rem);
+@9px          : unit( (9 / @emSize), rem);
+@10px         : unit( (10 / @emSize), rem);
+@11px         : unit( (11 / @emSize), rem);
+@12px         : unit( (12 / @emSize), rem);
+@13px         : unit( (13 / @emSize), rem);
+@14px         : unit( (14 / @emSize), rem);
+
+@relative1px  : unit( (1 / @emSize), em);
+@relative2px  : unit( (2 / @emSize), em);
+@relative3px  : unit( (3 / @emSize), em);
+@relative4px  : unit( (4 / @emSize), em);
+@relative5px  : unit( (5 / @emSize), em);
+@relative6px  : unit( (6 / @emSize), em);
+@relative7px  : unit( (7 / @emSize), em);
+@relative8px  : unit( (8 / @emSize), em);
+@relative9px  : unit( (9 / @emSize), em);
+@relative10px : unit( (10 / @emSize), em);
+@relative11px : unit( (11 / @emSize), em);
+@relative12px : unit( (12 / @emSize), em);
+@relative13px : unit( (13 / @emSize), em);
+@relative14px : unit( (14 / @emSize), em);