diff --git a/phpBB/adm/style/admin.css b/phpBB/adm/style/admin.css
index a4fef1f4ec..9d281d4703 100644
--- a/phpBB/adm/style/admin.css
+++ b/phpBB/adm/style/admin.css
@@ -214,11 +214,23 @@ li {
 }
 
 #main {
-	margin: 0 0 0 210px;
+	float: right;
+	width: 100%;
+	margin: 0 0 0 -210px;
 }
 
 .rtl #main {
-	margin: 0 210px 0 0;
+	float: right;
+	margin: 0 -210px 0 0;
+}
+
+.main {
+	margin-left: 210px;
+}
+
+.rtl .main {
+	margin-left: 0;
+	margin-right: 210px;
 }
 
 #page-body.simple-page-body {
@@ -258,7 +270,7 @@ li {
 		margin-top: 5px;
 	}
 
-	#main, .rtl #main {
+	#main, .rtl #main, .main, .rtl .main {
 		float: none;
 		width: auto;
 		margin: 0;
diff --git a/phpBB/adm/style/install_footer.html b/phpBB/adm/style/install_footer.html
index 7a5fc666f8..c5356e7b9d 100644
--- a/phpBB/adm/style/install_footer.html
+++ b/phpBB/adm/style/install_footer.html
@@ -1,7 +1,7 @@
-
-					</div>
+						</div>
+					</div><!-- /#main -->
 				</div>
-		</div>
+		</div><!-- /#acp -->
 	</div>
 
 	<div id="page-footer">
diff --git a/phpBB/adm/style/install_header.html b/phpBB/adm/style/install_header.html
index 182abe8875..d2dbf4bea7 100644
--- a/phpBB/adm/style/install_header.html
+++ b/phpBB/adm/style/install_header.html
@@ -76,3 +76,4 @@ function dE(n, s, type)
 					</div>
 
 					<div id="main" class="install-body">
+						<div class="main">
\ No newline at end of file
diff --git a/phpBB/adm/style/install_update_diff.html b/phpBB/adm/style/install_update_diff.html
index 3f2d1b71f4..c27304a425 100644
--- a/phpBB/adm/style/install_update_diff.html
+++ b/phpBB/adm/style/install_update_diff.html
@@ -34,7 +34,7 @@ window.onresize = resize_panel;
 <style type="text/css">
 /* <![CDATA[ */
 
-#main {
+#main, .rtl #main {
 	font-size: 1em;
 	line-height: 0.7em;
 	margin: 0;
diff --git a/phpBB/adm/style/overall_footer.html b/phpBB/adm/style/overall_footer.html
index 98a3a598e4..3c291842dc 100644
--- a/phpBB/adm/style/overall_footer.html
+++ b/phpBB/adm/style/overall_footer.html
@@ -1,7 +1,7 @@
-
-					</div>
+						</div>
+					</div><!-- /#main -->
 				</div>
-		</div>
+		</div><!-- /#acp -->
 	</div>
 
 	<div id="page-footer">
diff --git a/phpBB/adm/style/overall_header.html b/phpBB/adm/style/overall_header.html
index 658f1c49b0..eb16c61fd1 100644
--- a/phpBB/adm/style/overall_header.html
+++ b/phpBB/adm/style/overall_header.html
@@ -157,3 +157,4 @@ function popup(url, width, height, name)
 					</div>
 	
 					<div id="main">
+						<div class="main">