Minor UI changes (#3078)

Updating navbar dropdown

Updating margin on login page

webapp/sass/layout/_post.scss

@@ -506,6 +506,7 @@ body.ios {
             height: 26px;
             line-height: 25px;
             padding: 0 7px;
+            width: auto;
 
             .post-image__thumbnail {
                 display: none;