diff --git a/resources/classes/menu.php b/resources/classes/menu.php
index c7ea193f58..4df58f2e85 100644
--- a/resources/classes/menu.php
+++ b/resources/classes/menu.php
@@ -1158,13 +1158,7 @@ if (!class_exists('menu')) {
 			if ($_SESSION['theme']['menu_side_state']['text'] != 'expanded' && $_SESSION['theme']['menu_side_state']['text'] != 'hidden') {
 				$content_container_onclick = "onclick=\"clearTimeout(menu_side_contract_timer); if ($(window).width() >= 576) { menu_side_contract(); }\"";
 			}
-			//explicitly set content container width when side menu enabled
-			switch ($_SESSION['theme']['menu_side_state']['text']) {
-				case 'expanded': $content_container_width = $_SESSION['theme']['menu_side_width_expanded']['text'] ?? 225; break;
-				case 'hidden': $content_container_width = 0; break;
-				default: $content_container_width = $_SESSION['theme']['menu_side_width_contracted']['text'] ?? 60;
-			}
-			$html .= "<div id='content_container' style='width: calc(100% - ".$content_container_width."px);' ".$content_container_onclick.">\n";
+			$html .= "<div id='content_container' ".$content_container_onclick.">\n";
 			$html .= "	<div id='body_header'>\n";
 			//header: left
 				$html .= "<div class='float-left'>\n";
diff --git a/themes/default/css.php b/themes/default/css.php
index c4db204ab5..edf733a12c 100644
--- a/themes/default/css.php
+++ b/themes/default/css.php
@@ -986,7 +986,19 @@ else { //default: white
 
 	@media (max-width: 575.98px) {
 		div#content_container {
-			width: 100%;
+			<?php
+			if ($_SESSION['theme']['menu_style']['text'] == 'side') {
+				switch ($_SESSION['theme']['menu_side_state']['text']) {
+					case 'expanded': $content_container_width = $_SESSION['theme']['menu_side_width_expanded']['text'] ?? 225; break;
+					case 'hidden': $content_container_width = 0; break;
+					default: $content_container_width = $_SESSION['theme']['menu_side_width_contracted']['text'] ?? 60;
+				}
+			}
+			else {
+				$content_container_width = 0;
+			}
+			?>
+			width: calc(100% - <?=$content_container_width?>);
 			}
 	}
 	@media (min-width: 576px) {