diff --git a/source/layouts/layout.html.erb b/source/layouts/layout.html.erb
index 3e71195..49d0a70 100644
--- a/source/layouts/layout.html.erb
+++ b/source/layouts/layout.html.erb
@@ -21,8 +21,8 @@
     />
     <link
       rel="stylesheet"
-      href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css"
-      integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3"
+      href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.8/dist/css/bootstrap.min.css"
+      integrity="sha384-sRIl4kxILFvY47J16cr9ZwB07vP4J8+LH7qKQnuqkuIAvNWLzeN8tE5YBujZqJLB"
       crossorigin="anonymous"
     />
     <%= stylesheet_link_tag "vendor/codemirror" %>
@@ -32,13 +32,13 @@
 
     <%# Scripts %>
     <script
-      src="https://cdn.jsdelivr.net/npm/@popperjs/core@2.10.2/dist/umd/popper.min.js"
-      integrity="sha384-7+zCNj/IqJ95wo16oMtfsKbZ9ccEh31eOz1HGyDuCQ6wgnyJNSYdrPa03rtR1zdB"
+      src="https://cdn.jsdelivr.net/npm/@popperjs/core@2.11.8/dist/umd/popper.min.js"
+      integrity="sha384-I7E8VVD/ismYTF4hNIPjVp/Zjvgyol6VFvRkX/vR+Vc4jQkC+hVqc2pM8ODewa9r"
       crossorigin="anonymous"
     ></script>
     <script
-      src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/js/bootstrap.min.js"
-      integrity="sha384-QJHtvGhmr9XOIpI6YVutG+2QOK9T+ZnN4kzFN1RtK3zEFEIsxhlmWl5/YESvpZ13"
+      src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.8/dist/js/bootstrap.min.js"
+      integrity="sha384-G/EV+4j2dNv+tEPo3++6LCgdCROaejBqfUeNjuKAiuXbjrxilcCdDz6ZAVfHWe1Y"
       crossorigin="anonymous"
     ></script>
     <%= javascript_include_tag "vendor/codemirror-compressed-4.8" %>
diff --git a/source/stylesheets/application.css.scss b/source/stylesheets/application.css.scss
index 0a88d6b..761617e 100644
--- a/source/stylesheets/application.css.scss
+++ b/source/stylesheets/application.css.scss
@@ -68,6 +68,12 @@ body {
 }
 
 .language-menu-toggle {
+  // Bootstrap 5.3 gives a plain .btn.nav-link the navbar's font and no usable border or focus ring states
+  --bs-btn-hover-border-color: var(--nav-border-color);
+  --bs-btn-active-border-color: var(--nav-border-color);
+  --bs-btn-focus-box-shadow: 0 0 0 var(--bs-focus-ring-width) var(--bs-focus-ring-color);
+  font-size: 1rem;
+  font-weight: normal;
   background: transparent;
   border: 1px solid var(--nav-border-color);
 
@@ -252,11 +258,6 @@ pre {
     background: white;
     padding: .25em;
     border-radius: .5rem;
-
-    // Undo Bootstrap's bidi-override on pre, which lays out RTL text in logical order
-    pre {
-      unicode-bidi: normal;
-    }
   }
 }