diff --git a/index.html b/index.html
index 3140d8c..c9ec589 100644
--- a/index.html
+++ b/index.html
@@ -88,6 +88,9 @@
     <div id="sidebar">
       <div id="sidebar-header">BUFFERS</div>
       <div id="buffer-list"></div>
+      <div id="sidebar-footer">
+        <button id="sidebar-join-btn" class="sidebar-footer-btn">＋ JOIN</button>
+      </div>
     </div>
 
     <!-- Main area -->