diff --git a/html/mainPage/index.html b/html/mainPage/index.html
index 14d3e23..24f1a05 100644
--- a/html/mainPage/index.html
+++ b/html/mainPage/index.html
@@ -126,7 +126,7 @@ <h3>Scripting (beta)</h3>
     </div>
     <div class="split" id="sidebar">
         <div class="toolbar tab">
-            <button class="tablinks-rightpanel active" onclick="openMenu(event, 'tree', '-rightpanel')">Data</button>
+            <button class="tab-button tablinks-rightpanel active" onclick="openMenu(event, 'tree', '-rightpanel')">Data</button>
             <!-- <button class="tablinks-rightpanel" onclick="openMenu(event, 'test', '-rightpanel')">Tab 2</button> !-->
         </div>
         <div class="box" id="sidebar-box">