Add pinned posts (#4217)

webapp/sass/layout/_content.scss

@@ -9,10 +9,20 @@
         .search-btns {
             display: none;
         }
-        .header-list__members {
+        .header-list__right {
+            // the negative margin-right is used
+            // to prevent the icons in the header from
+            // moving to the left when the RHS is open
+            //
+            // the below z-index is used to ensure the icons
+            // stays on the top and don't get hidden by the
+            // search's input block
+            position: relative;
+            z-index: 6;
+
             margin-right: -18px;
-            float: right;
             padding-right: 0px !important;
+            float: right;
         }
     }
 
@@ -23,10 +33,20 @@
         .search-btns {
             display: none;
         }
-        .header-list__members {
+        .header-list__right {
+            // the negative margin-right is used
+            // to prevent the icons in the header from
+            // moving to the left when the RHS is open
+            //
+            // the below z-index is used to ensure the icons
+            // stays on the top and don't get hidden by the
+            // search's input block
+            position: relative;
+            z-index: 6;
+
             margin-right: -18px;
-            float: right;
             padding-right: 0px !important;
+            float: right
         }
     }
 }