Move all variables into custom-variables file

static/css/custom-variables.less

@@ -3,9 +3,15 @@
 @page-footer-height: 50px;
 @page-footer-height-subset: 16;
 
+@page-header-color: #8B0000;
+
 @navbar-top-background-color: #FAFAFA;
 @navbar-top-background-image: linear-gradient(to bottom, #FFF, #F2F2F2);
 @navbar-top-border: 1px solid #D4D4D4;
 @navbar-top-box-shadow: 0px 1px 10px rgba(0, 0, 0, 0.1);
 
+@font-family-sans-serif:  'Open Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif;
+@font-family-monospace: Roboto, Menlo, Monaco, Consolas, "Courier New", monospace;
+@headings-font-family: Lora, Baskerville, Garamond, Georgia, 'DejaVu Serif', 'Times New Roman', Times, Serif;
 @grid-float-breakpoint: @screen-md-min;
+@page-header-border-color: #8f8686;

static/css/elegant.less

@@ -6,13 +6,6 @@
 @import url(http://fonts.googleapis.com/css?family=Roboto);
 @import url(http://fonts.googleapis.com/css?family=Lora);
 
-@page-header-border-color: #8f8686;
-@page-header-color: #8B0000;
-@font-family-sans-serif:  'Open Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif;
-@font-family-monospace: Roboto, Menlo, Monaco, Consolas, "Courier New", monospace;
-@headings-font-family: Lora, Baskerville, Garamond, Georgia, 'DejaVu Serif', 'Times New Roman', Times, Serif;
-
-
 .mixin-no-color-no-decoration() {
     color: inherit;
     text-decoration: none;