Move <main> and .sidebar markup out of PHP

Add more efficient LESS with variables

Add new line to _variables.less

Add sidebar class to body element instead of main element

Change body sidebar class to .sidebar-active

Change body sidebar class to .sidebar-primary

Correct spacing issues

assets/less/_variables.less

@@ -8,3 +8,7 @@
 // -------------------------
 
 @icon-font-path:        "../vendor/bootstrap/fonts/";
+
+@main-sm-columns:       @grid-columns;
+
+@sidebar-sm-columns:    4;

assets/less/layouts/_general.less

@@ -2,4 +2,9 @@
 .wrap { }
 
 // Main content area
-.main { }
+.main {
+  .make-sm-column(@main-sm-columns);
+  .sidebar-primary & {
+    .make-sm-column(@main-sm-columns - @sidebar-sm-columns);
+  }
+}

assets/less/layouts/_sidebar.less

@@ -1 +1,3 @@
-.sidebar { }
+.sidebar {
+  .make-sm-column(@sidebar-sm-columns);
+}