use navigate-small class

src/scripts/app.tag

@@ -1,5 +1,5 @@
 <app>
-  <div class="show-md show-sm show-xs navigate dropdown dropdown-right">
+  <div class="show-md show-sm show-xs navigate-small dropdown dropdown-right">
     <button onclick={this.menuOn} class="mobile-navigate btn btn-link navigate-item dropdown-toggle" tabindex="0">
       <i class="bar-menu fa fa-bars" aria-hidden="true"></i>
     </button>

src/styles/riotblog.scss

@@ -99,6 +99,12 @@ p, h6, h4 {
 }
 
 .navigate {
+  width: 20%;
+  margin-bottom: 25px !important;
+  margin: auto !important;
+}
+
+.navigate-small {
   width: $menuWidth;
   margin-bottom: 25px !important;
   margin: auto !important;