diff --git a/doc/_static/breathe.css b/doc/_static/breathe.css
index 2a1534b0..96e5a497 100644
--- a/doc/_static/breathe.css
+++ b/doc/_static/breathe.css
@@ -14,15 +14,3 @@
 .container .breathe-sectiondef {
   width: inherit;
 }
-
-.github-btn {
-  border: 0;
-  overflow: hidden;
-}
-
-.jumbotron {
-  background-size: 100% 4px;
-  background-repeat: repeat-y;
-  color: white;
-  text-align: center;
-}
diff --git a/doc/fmt.scss b/doc/fmt.scss
index 6725100b..35840907 100644
--- a/doc/fmt.scss
+++ b/doc/fmt.scss
@@ -10,6 +10,7 @@ $header-bg: #094d75;
   text-align: center;
 }
 
+// Keep content not too wide for better readability.
 .content, .fmt-navbar-content {
   @extend .col-md-10;
   @extend .offset-md-1;
@@ -19,6 +20,42 @@ $header-bg: #094d75;
 
 @import 'bootstrap/scss/bootstrap';
 
+$bd-gutter-x: 3rem;
+
+// Based on _component-examples.scss in https://github.com/twbs/bootstrap.
+.highlight {
+  position: relative;
+  padding: .75rem ($bd-gutter-x * .5);
+  background-color: #f5f5f5; // var(--bd-pre-bg);
+
+  @include media-breakpoint-up(md) {
+    padding: .75rem 1.25rem;
+    @include border-radius(calc(var(--bs-border-radius) - 1px));
+  }
+
+  @include media-breakpoint-up(lg) {
+    pre {
+      margin-right: 1.875rem;
+    }
+  }
+
+  pre {
+    padding: .25rem 0 .25rem;
+    margin-top: .8125rem;
+    margin-bottom: 0;
+    overflow: overlay;
+    white-space: pre;
+    background-color: transparent;
+    border: 0;
+  }
+
+  pre code {
+    @include font-size(inherit);
+    color: var(--bs-body-color); // Effectively the base text color
+    word-wrap: normal;
+  }
+}
+
 /*$icon-font-path: "fonts/";
 
 html {
@@ -35,14 +72,6 @@ div.sphinxsidebar {
   margin-left: 0;
 }
 
-// Keep content not too wide for better readability.
-.navbar-content, .content {
-  @include make-md-column-offset(1);
-  @include make-md-column(10);
-  @include make-lg-column-offset(2);
-  @include make-lg-column(8);
-}
-
 .footer {
   padding-top: 20px;
   padding-bottom: 20px;
@@ -73,9 +102,4 @@ td {
 p.rubric {
   margin-top: 10px;
 }
-
-.github-btn {
-  border: 0;
-  overflow: hidden;
-}
 */
\ No newline at end of file