diff --git a/modules/forums/client/less/forum.less b/modules/forums/client/less/forum.less
index 971417ab..cb1648bf 100644
--- a/modules/forums/client/less/forum.less
+++ b/modules/forums/client/less/forum.less
@@ -256,48 +256,35 @@
 
 /* csslint ignore:start */
 .box-uib-and-post-btn {
-    display: -webkit-box;
-    display: -moz-box;
+    display: -webkit-flex;
     display: -ms-flexbox;
-    display: box;
+    display: flex;
 
-    -webkit-box-orient: horizontal;
-    -moz-box-orient: horizontal;
+    -webkit-flex-direction: row;
+    -moz-flex-direction: row;
     -ms-flex-direction: row;
-    box-orient: horizontal;
+    flex-direction: row;
     @media (max-width: @screen-sm-max) {
-        -webkit-box-orient: vertical;
-        -moz-box-orient: vertical;
+        -webkit-flex-direction: column;
+        -moz-flex-direction: column;
         -ms-flex-direction: column;
-        box-orient: vertical;
+        flex-direction: column;
     }
     .box-uib {
-        -webkit-box-ordinal-group: 1;
-        -moz-box-ordinal-group: 1;
-        -ms-flex-order: 1;
-        box-ordinal-group: 1;
+        order: 1;
         @media (max-width: @screen-sm-max) {
-            -webkit-box-ordinal-group: 2;
-            -moz-box-ordinal-group: 2;
-            -ms-flex-order: 2;
-            box-ordinal-group: 2;
+            order: 2;
         }
     }
     .box-post-btn {
         margin: 10px 0;
         position: absolute;
         right: 15px;
-        -webkit-box-ordinal-group: 2;
-        -moz-box-ordinal-group: 2;
-        -ms-flex-order: 2;
-        box-ordinal-group: 2;
+        order: 2;
         @media (max-width: @screen-sm-max) {
             margin: 0 0;
             position: inherit;
-            -webkit-box-ordinal-group: 1;
-            -moz-box-ordinal-group: 1;
-            -ms-flex-order: 1;
-            box-ordinal-group: 1;
+            order: 1;
         }
     }
 }
@@ -417,12 +404,6 @@
                 img {
                     max-width: 100%;
                     height: auto;
-                    /* csslint ignore:start */
-                    -webkit-box-flex: 1;
-                    -moz-box-flex: 1;
-                    -ms-box-flex: 1;
-                    flex: 1;
-                    /* csslint ignore:end */
                 }
             }
         }