diff --git a/ace/index.html b/ace/index.html
index 1568073..76aa14b 100644
--- a/ace/index.html
+++ b/ace/index.html
@@ -11,10 +11,12 @@
             margin: 0;
             padding: 0;
             overflow: hidden;
+            background: #232B30;
         }
         .inner {
             margin-top: 28px;
-            padding: 20px;
+            margin-left: 6px;
+			margin-right: 6px;
             position: absolute;
             top: 0;
             bottom: 0;
@@ -58,7 +60,7 @@
             <!--<button id="btnSave" onClick="save()" class="btn btn_g">save</button>-->
             <button id="btnUndo" onClick="editor.undo()" class="btn">↶</button>
             <button id="btnRedo" onClick="editor.redo()" class="btn btn_g">↷</button>
-          	<button id="btnFs" onclick="toggleFullscreen()" class="btn">FS</button>
+          	<button id="btnFs" onclick="toggleFullscreen()" class="btn">◻</button>
         </div>
         <div class="inner" id="editor"></div>
         
@@ -82,7 +84,11 @@
             function updateToolbar() {
                 document.getElementById("btnUndo").disabled = !editor.session.getUndoManager().hasUndo();
                 document.getElementById("btnRedo").disabled = !editor.session.getUndoManager().hasRedo();
-                document.getElementById("btnFs").visible = !window.fullScreen;
+                if (!window.fullscreen) {
+                  document.getElementById("btnFs").style.display = "none";
+                } else {
+                  document.getElementById("btnFs").style.display = "block";
+                }
             }
             editor.on("input", updateToolbar);