feat: add css to port editor

Author: akinsey

src/assets/scss/_mixins.scss

@@ -38,6 +38,13 @@
   }
 }
 
+@mixin break-max-xlarge {
+  @media screen and (max-width: #{$xlarge}) {
+    @content;
+  }
+}
+
+
 @mixin break-min-desktop {
   @media screen and (min-width: #{$desktop}) {
     @content;

src/assets/scss/_variables.scss

@@ -3,6 +3,7 @@
 // grid layout
 $view-maxWidth: 1300px;
 $sidebarWidth: 240px;
+$max-width: 960px;
 
 // Posts layout variables
 $postUserWidth: 80px;
@@ -133,7 +134,8 @@ $border-quote: 2px solid rgba($border-color, 0.5);
 $tablet:  767px;
 $desktop: 960px;
 $medium: 1024px;
-$large:   1280px;
+$large:  1280px;
+$xlarge: 1400px;
 
 @import 'mixins';
 @import 'vendor/vendor';