Merge pull request #459 from ember-learn/margin-hr-mobile

Fix mobile margin for <hr>

Author: MinThaMie

addon/styles/global.css

@@ -253,20 +253,12 @@ img {
   max-width: 100%;
 }
 
-/*
-@media (max-width: 1280px) and (min-width: 421px) {
-  body,
-  html {
+@media (max-width: 1080px) {
+  hr {
+    margin: var(--spacing-2) 0px;
   }
 }
 
-@media (max-width: 520px) {
-  body,
-  html {
-  }
-}
-*/
-
 /* move beyond this point */
 
 .content-section {