diff --git a/.env b/.env
index cc86446..a61fb32 100644
--- a/.env
+++ b/.env
@@ -1 +1 @@
-MDBOOK_VERSION=0.4.25
+MDBOOK_VERSION=0.4.28
diff --git a/404.html b/404.html
index a54b8b0..376f367 100644
--- a/404.html
+++ b/404.html
@@ -33,6 +33,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
@@ -70,10 +71,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -184,5 +187,6 @@
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/additional_resources/design-principles.html b/additional_resources/design-principles.html
index 8d72c20..24a4128 100644
--- a/additional_resources/design-principles.html
+++ b/additional_resources/design-principles.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -259,5 +262,6 @@ Construction</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/additional_resources/index.html b/additional_resources/index.html
index 76432a4..8145d35 100644
--- a/additional_resources/index.html
+++ b/additional_resources/index.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -211,5 +214,6 @@ Nicholas Cameron at LinuxConfAu (2018)</li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/anti_patterns/borrow_clone.html b/anti_patterns/borrow_clone.html
index 039bd76..aa22c10 100644
--- a/anti_patterns/borrow_clone.html
+++ b/anti_patterns/borrow_clone.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -259,5 +262,6 @@ cases in which <code>.clone()</code> is not necessary, like <a href="https://rus
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/anti_patterns/deny-warnings.html b/anti_patterns/deny-warnings.html
index 9d23da5..cd68d7a 100644
--- a/anti_patterns/deny-warnings.html
+++ b/anti_patterns/deny-warnings.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -272,5 +275,6 @@ certain that there will be more deprecated APIs in the future.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/anti_patterns/deref.html b/anti_patterns/deref.html
index 9dc5b3e..abfc52b 100644
--- a/anti_patterns/deref.html
+++ b/anti_patterns/deref.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -298,5 +301,6 @@ or <a href="https://crates.io/crates/ambassador">ambassador</a></li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/anti_patterns/index.html b/anti_patterns/index.html
index 2762e7c..9cabded 100644
--- a/anti_patterns/index.html
+++ b/anti_patterns/index.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -203,5 +206,6 @@ For example, a process can be an anti-pattern, too.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/css/chrome.css b/css/chrome.css
index 59eae11..29992f7 100644
--- a/css/chrome.css
+++ b/css/chrome.css
@@ -2,12 +2,6 @@
 
 @import 'variables.css';
 
-::-webkit-scrollbar {
-    background: var(--bg);
-}
-::-webkit-scrollbar-thumb {
-    background: var(--scrollbar);
-}
 html {
     scrollbar-color: var(--scrollbar) var(--bg);
 }
@@ -18,6 +12,19 @@ a > .hljs {
     color: var(--links);
 }
 
+/*
+    body-container is necessary because mobile browsers don't seem to like
+    overflow-x on the body tag when there is a <meta name="viewport"> tag.
+*/
+#body-container {
+    /*
+        This is used when the sidebar pushes the body content off the side of
+        the screen on small screens. Without it, dragging on mobile Safari
+        will want to reposition the viewport in a weird way.
+    */
+    overflow-x: clip;
+}
+
 /* Menu Bar */
 
 #menu-bar,
diff --git a/functional/generics-type-classes.html b/functional/generics-type-classes.html
index 0fce36d..ddb5fa6 100644
--- a/functional/generics-type-classes.html
+++ b/functional/generics-type-classes.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -449,5 +452,6 @@ and
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/functional/index.html b/functional/index.html
index 4d94439..65092b2 100644
--- a/functional/index.html
+++ b/functional/index.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -206,5 +209,6 @@ imperative statements which change the state of the program.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/functional/lenses.html b/functional/lenses.html
index b22b57e..6311214 100644
--- a/functional/lenses.html
+++ b/functional/lenses.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -507,5 +510,6 @@ Accessors</a></li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/functional/paradigms.html b/functional/paradigms.html
index 6d63065..fab66ea 100644
--- a/functional/paradigms.html
+++ b/functional/paradigms.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -257,5 +260,6 @@ result. This process continues until we get to the last element in the range,
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/coercion-arguments.html b/idioms/coercion-arguments.html
index c66c938..f91dbea 100644
--- a/idioms/coercion-arguments.html
+++ b/idioms/coercion-arguments.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -305,5 +308,6 @@ by Herman J. Radtke III</li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/concat-format.html b/idioms/concat-format.html
index ca0d57c..c3dbe03 100644
--- a/idioms/concat-format.html
+++ b/idioms/concat-format.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -222,5 +225,6 @@ string has been pre-allocated to the expected size).</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/ctor.html b/idioms/ctor.html
index c2ae419..84ffd34 100644
--- a/idioms/ctor.html
+++ b/idioms/ctor.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -303,5 +306,6 @@ implementing both, <code>Default</code> and <code>new</code>.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/default.html b/idioms/default.html
index ce74581..4b935e0 100644
--- a/idioms/default.html
+++ b/idioms/default.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -252,5 +255,6 @@ not be &quot;default&quot;</li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/deref.html b/idioms/deref.html
index f5e250a..5486863 100644
--- a/idioms/deref.html
+++ b/idioms/deref.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -256,5 +259,6 @@ slicing syntax. The target will be the borrowed view.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/dtor-finally.html b/idioms/dtor-finally.html
index 4843053..3d3d631 100644
--- a/idioms/dtor-finally.html
+++ b/idioms/dtor-finally.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -265,5 +268,6 @@ resources in an unexpected state.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/ffi/accepting-strings.html b/idioms/ffi/accepting-strings.html
index a2abad1..dee3c70 100644
--- a/idioms/ffi/accepting-strings.html
+++ b/idioms/ffi/accepting-strings.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -321,5 +324,6 @@ completely crash.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/ffi/errors.html b/idioms/ffi/errors.html
index c7095bb..f828cd6 100644
--- a/idioms/ffi/errors.html
+++ b/idioms/ffi/errors.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -316,5 +319,6 @@ to C.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/ffi/intro.html b/idioms/ffi/intro.html
index b21d22a..492fb57 100644
--- a/idioms/ffi/intro.html
+++ b/idioms/ffi/intro.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -213,5 +216,6 @@ sentinel return values (such as <code>NULL</code> pointers)</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/ffi/passing-strings.html b/idioms/ffi/passing-strings.html
index ff8cf97..56a9687 100644
--- a/idioms/ffi/passing-strings.html
+++ b/idioms/ffi/passing-strings.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -284,5 +287,6 @@ system's ability to return zeroed memory (which is quite fast).</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/index.html b/idioms/index.html
index f3fd257..5f83db0 100644
--- a/idioms/index.html
+++ b/idioms/index.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -212,5 +215,6 @@ goal in design, and unnecessary complexity should be avoided&quot;.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/mem-replace.html b/idioms/mem-replace.html
index 92a457c..ade6958 100644
--- a/idioms/mem-replace.html
+++ b/idioms/mem-replace.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -288,5 +291,6 @@ anti-pattern in a specific case.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/on-stack-dyn-dispatch.html b/idioms/on-stack-dyn-dispatch.html
index 3f84d4f..f84ef64 100644
--- a/idioms/on-stack-dyn-dispatch.html
+++ b/idioms/on-stack-dyn-dispatch.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -268,5 +271,6 @@ optional reference.</li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/option-iter.html b/idioms/option-iter.html
index cdaf2b8..f61a86b 100644
--- a/idioms/option-iter.html
+++ b/idioms/option-iter.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -253,5 +256,6 @@ for converting an <code>Option</code> to a zero- or one-element slice.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/pass-var-to-closure.html b/idioms/pass-var-to-closure.html
index c5d48d6..a14c279 100644
--- a/idioms/pass-var-to-closure.html
+++ b/idioms/pass-var-to-closure.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -244,5 +247,6 @@ moved.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/priv-extend.html b/idioms/priv-extend.html
index 9b64ee6..3195dda 100644
--- a/idioms/priv-extend.html
+++ b/idioms/priv-extend.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -307,5 +310,6 @@ there is rarely a sensible action to take in this scenario.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/return-consumed-arg-on-error.html b/idioms/return-consumed-arg-on-error.html
index f0f5291..b1a2732 100644
--- a/idioms/return-consumed-arg-on-error.html
+++ b/idioms/return-consumed-arg-on-error.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -244,5 +247,6 @@ You can get original vector back using <code>FromUtf8Error::into_bytes</code> me
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/rustdoc-init.html b/idioms/rustdoc-init.html
index d1df3b9..dde43c2 100644
--- a/idioms/rustdoc-init.html
+++ b/idioms/rustdoc-init.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -269,5 +272,6 @@ crate's public API.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/idioms/temporary-mutability.html b/idioms/temporary-mutability.html
index ef3017e..b88293b 100644
--- a/idioms/temporary-mutability.html
+++ b/idioms/temporary-mutability.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -224,5 +227,6 @@ One more line to return data from block or redefine variable.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/index.html b/index.html
index d67202f..ef462eb 100644
--- a/index.html
+++ b/index.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -224,5 +227,6 @@ anti-patterns create more problems.</li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/intro.html b/intro.html
index d67202f..ef462eb 100644
--- a/intro.html
+++ b/intro.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -224,5 +227,6 @@ anti-patterns create more problems.</li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/behavioural/RAII.html b/patterns/behavioural/RAII.html
index 734e0ec..cf2cc60 100644
--- a/patterns/behavioural/RAII.html
+++ b/patterns/behavioural/RAII.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -292,5 +295,6 @@ works just as well.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/behavioural/command.html b/patterns/behavioural/command.html
index 118b388..a42f17e 100644
--- a/patterns/behavioural/command.html
+++ b/patterns/behavioural/command.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -397,5 +400,6 @@ dynamic dispatch provides flexibility when we structure our application.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/behavioural/interpreter.html b/patterns/behavioural/interpreter.html
index 05a8a94..a23f553 100644
--- a/patterns/behavioural/interpreter.html
+++ b/patterns/behavioural/interpreter.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -324,5 +327,6 @@ fn main() {
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/behavioural/intro.html b/patterns/behavioural/intro.html
index 381d040..39e0c65 100644
--- a/patterns/behavioural/intro.html
+++ b/patterns/behavioural/intro.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -202,5 +205,6 @@ By doing so, these patterns increase flexibility in carrying out communication.<
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/behavioural/newtype.html b/patterns/behavioural/newtype.html
index d0e91e0..e2d700c 100644
--- a/patterns/behavioural/newtype.html
+++ b/patterns/behavioural/newtype.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -284,5 +287,6 @@ builtin traits on newtypes.</li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/behavioural/strategy.html b/patterns/behavioural/strategy.html
index 3a94e19..c626de5 100644
--- a/patterns/behavioural/strategy.html
+++ b/patterns/behavioural/strategy.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -349,5 +352,6 @@ fn main() {
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/behavioural/visitor.html b/patterns/behavioural/visitor.html
index f598157..12ff379 100644
--- a/patterns/behavioural/visitor.html
+++ b/patterns/behavioural/visitor.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -289,5 +292,6 @@ a new version of the visited data structure.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/creational/builder.html b/patterns/creational/builder.html
index 6490923..a6c9059 100644
--- a/patterns/creational/builder.html
+++ b/patterns/creational/builder.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -292,5 +295,6 @@ implementing this pattern while avoiding the boilerplate.</li>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/creational/fold.html b/patterns/creational/fold.html
index 4ecb2c1..72c936f 100644
--- a/patterns/creational/fold.html
+++ b/patterns/creational/fold.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -296,5 +299,6 @@ the old one.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/creational/intro.html b/patterns/creational/intro.html
index 227d696..5cc130a 100644
--- a/patterns/creational/intro.html
+++ b/patterns/creational/intro.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -204,5 +207,6 @@ patterns solve this problem by somehow controlling this object creation.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/ffi/export.html b/patterns/ffi/export.html
index 9c60fec..b5cf26e 100644
--- a/patterns/ffi/export.html
+++ b/patterns/ffi/export.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -414,5 +417,6 @@ It is up to the best judgement of the programmer as to who their audience is.</p
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/ffi/intro.html b/patterns/ffi/intro.html
index f25043a..a9057bb 100644
--- a/patterns/ffi/intro.html
+++ b/patterns/ffi/intro.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -211,5 +214,6 @@ together into an opaque &quot;object&quot;</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/ffi/wrappers.html b/patterns/ffi/wrappers.html
index bea2d62..661fd18 100644
--- a/patterns/ffi/wrappers.html
+++ b/patterns/ffi/wrappers.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -323,5 +326,6 @@ These observations may happen <em>any time after</em> the mutable reference is c
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/index.html b/patterns/index.html
index 462b2c7..bce06d4 100644
--- a/patterns/index.html
+++ b/patterns/index.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -218,5 +221,6 @@ in Rust because we can just use <a href="https://doc.rust-lang.org/book/traits.h
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/structural/compose-structs.html b/patterns/structural/compose-structs.html
index 3ba7c9f..afa9b52 100644
--- a/patterns/structural/compose-structs.html
+++ b/patterns/structural/compose-structs.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -277,5 +280,6 @@ borrow all of <code>a</code>, which would make this pattern useless.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/structural/intro.html b/patterns/structural/intro.html
index b3755b0..b96fd05 100644
--- a/patterns/structural/intro.html
+++ b/patterns/structural/intro.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -202,5 +205,6 @@ among entities.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/structural/small-crates.html b/patterns/structural/small-crates.html
index 257967e..2c2da48 100644
--- a/patterns/structural/small-crates.html
+++ b/patterns/structural/small-crates.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -236,5 +239,6 @@ query the number of CPUs on a machine.</p>
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/patterns/structural/unsafe-mods.html b/patterns/structural/unsafe-mods.html
index ac95629..9174902 100644
--- a/patterns/structural/unsafe-mods.html
+++ b/patterns/structural/unsafe-mods.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "../../";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -228,5 +231,6 @@ in which case the onus is on them to guarantee the validity of the contents.</li
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
diff --git a/print.html b/print.html
index e17fee9..34ac0d7 100644
--- a/print.html
+++ b/print.html
@@ -33,6 +33,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
@@ -70,10 +71,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -4026,5 +4029,6 @@ Construction</p>
         });
         </script>
 
+    </div>
     </body>
 </html>
diff --git a/translations.html b/translations.html
index cc9830d..b82a84d 100644
--- a/translations.html
+++ b/translations.html
@@ -32,6 +32,7 @@
 
     </head>
     <body>
+    <div id="body-container">
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
@@ -69,10 +70,12 @@
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
             var html = document.querySelector('html');
-            var sidebar = 'hidden';
+            var sidebar = null;
             if (document.body.clientWidth >= 1080) {
                 try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                 sidebar = sidebar || 'visible';
+            } else {
+                sidebar = 'hidden';
             }
             html.classList.remove('sidebar-visible');
             html.classList.add("sidebar-" + sidebar);
@@ -202,5 +205,6 @@
         <!-- Custom JS scripts -->
 
 
+    </div>
     </body>
 </html>
