diff --git a/core/modules/forum/css/forum.module-rtl.css b/core/modules/forum/css/forum.module-rtl.css
index 0e5d3ed..fece3f6 100644
--- a/core/modules/forum/css/forum.module-rtl.css
+++ b/core/modules/forum/css/forum.module-rtl.css
@@ -3,11 +3,11 @@
  * Right-to-left styling for the Forum module.
  */
 
-#forum .icon {
+.forum .icon {
   float: right;
   margin: 0 0 0 9px;
 }
-#forum div.indent {
+.forum .indent {
   margin-left: 0;
   margin-right: 20px;
 }
diff --git a/core/modules/forum/css/forum.module.css b/core/modules/forum/css/forum.module.css
index 0c4f8fc..f14f51e 100644
--- a/core/modules/forum/css/forum.module.css
+++ b/core/modules/forum/css/forum.module.css
@@ -3,19 +3,19 @@
  * Styling for the Forum module.
  */
 
-#forum .description {
+.forum .description {
   font-size: 0.9em;
   margin: 0.5em;
 }
-#forum td.created,
-#forum td.posts,
-#forum td.topics,
-#forum td.last-reply,
-#forum td.replies,
-#forum td.pager {
+.forum .created,
+.forum .posts,
+.forum .topics,
+.forum .last-reply,
+.forum .replies,
+.forum .pager {
   white-space: nowrap;
 }
-#forum .icon{
+.forum .icon{
   background-image: url(../../../misc/forum-icons.png);
   background-repeat: no-repeat;
   float: left; /* LTR */
@@ -23,25 +23,25 @@
   margin: 0 9px 0 0; /* LTR */
   width: 24px;
 }
-#forum .title {
+.forum .title {
   overflow: hidden;
 }
-#forum div.indent {
+.forum .indent {
   margin-left: 20px; /* LTR */
 }
 
-#forum .topic-status-new {
+.forum .topic-status-new {
   background-position: -24px 0;
 }
-#forum .topic-status-hot {
+.forum .topic-status-hot {
   background-position: -48px 0;
 }
-#forum .topic-status-hot-new {
+.forum .topic-status-hot-new {
   background-position: -72px 0;
 }
-#forum .topic-status-sticky {
+.forum .topic-status-sticky {
   background-position: -96px 0;
 }
-#forum .topic-status-closed {
+.forum .topic-status-closed {
   background-position: -120px 0;
 }
diff --git a/core/modules/forum/templates/forums.html.twig b/core/modules/forum/templates/forums.html.twig
index 59fff7d..ef1a441 100644
--- a/core/modules/forum/templates/forums.html.twig
+++ b/core/modules/forum/templates/forums.html.twig
@@ -17,7 +17,7 @@
  */
 #}
 {% if forums_defined %}
-  <div id="forum">
+  <div id="forum" class="forum">
     {{ forums }}
     {{ topics }}
   </div>