diff --git a/css/style.css b/css/style.css
index c4a5622..1aefdb7 100644
--- a/css/style.css
+++ b/css/style.css
@@ -235,12 +235,23 @@ body {
 }
 
 /* Main content grows so the footer is pushed to the bottom (sticky footer) */
-body > .container {
+body > .container,
+body > .container-wide {
 	flex: 1 0 auto;
 	width: 100%;
 	padding-bottom: var(--space-xl);
 }
 
+/* Wider container used on article pages that have a ToC sidebar.
+   Same gutter behaviour as Bootstrap's .container but with more breathing room. */
+.container-wide {
+	padding-right: 15px;
+	padding-left: 15px;
+	margin-right: auto;
+	margin-left: auto;
+	max-width: 1400px;
+}
+
 img {
 	max-width: 100%;
 	height: auto;
diff --git a/index.php b/index.php
index 20d4113..b8ed8cc 100644
--- a/index.php
+++ b/index.php
@@ -101,7 +101,7 @@
 	?>
 
 	<!-- Content -->
-	<div class="container">
+	<div class="<?php echo $hasHeadings ? 'container-wide' : 'container'; ?>">
 		<div class="row">
 
 			<?php if ($hasHeadings): ?>