Increase width of main content to better fill large screens sizes

assets/scss/_sidebar.scss

@@ -9,6 +9,9 @@
     @include span(2 of 12);
     @include suffix(0.25 of 12);
   }
+  @include breakpoint($x-large) {
+    padding-right: 0;
+  }
   h2, h3, h4, h5, h6 {
     font-family: $sans-serif-narrow;
   }