Changed used SCSS variable name due to renaming of variables by Moodle.

CHANGES.md

@@ -6,6 +6,7 @@ Changes
 
 ### Unreleased
 
+* 2018-05-14 - Changed used SCSS variable name due to renaming of variables by Moodle.
 * 2018-05-14 - Check compatibility for Moodle 3.5, no functionality change.
 
 ### Release v3.4-r5

scss/post.scss

@@ -268,7 +268,7 @@ body.loginbackgroundimage {
             position: inherit;
             left: inherit;
             font-weight: $headings-font-weight;
-            font-size: $font-size-h3;
+            font-size: $h3-font-size;
         }
     }
 }