v5.2.0 design refresh, plus responsive offcanvas classes (#35736)

* Add responsive offcanvas classes

- Updates navbar-expand classes to de-dupe some styles—these shouldn't interfere now.
- Adds some JS to the offcanvas component to help with responsiveness

Co-Authored-By: GeoSot <geo.sotis@gmail.com>

* Redesign homepage, docs, and examples

Homepage:

- New Bootstrap purple navbar
- Redesigned masthead
- Rewrote and redesigned homepage content
- Replace Copy text with icons like Bootstrap Icons site across all ClipboardJS instances
- Fixed padding issues in site footer
- Match homepage button styles to examples page, use gap instead of tons of responsive margin utils

Docs:

- New navbar, no more subnav. Migrated search and version picker into the main navbar and refreshed the design of it all, including the responsive toggles.
- New sidebar navigation is always expanded, and now features Bootstrap Icons alongside section headings
- Sidebar navigation autoscrolls to active link for better usability
- Subnav and navbar padding issues ironed out
- Enhanced the version picker in anticipation of v5.2: we can now link right to the same page in the previous version.
- Redesign callouts to add more color to our pages
- Collapse table of contents on mobile
- Cleanup and redesign button styles with CSS variables
- Update design for subnav version dropdown
- Update highlight and example to be full-width until md
- Improve the Added In badges
- Turn the ToC into a well on mobile
- Redesign code snippets to better house two action buttons

Examples:

- Redesign Examples page layout
- Add new example for responsive offcanvases in navbars

* Convert offcanvas to CSS vars

* Feat: add resize handler to Offcanvas.js.

If we could use as default the `.offcanvas` class without modifiers, we then, could add a simplified selector
The selector itself, ignores the .offcanvas class as it doesn't have any responsive behavior
The `aria-modal` addon is to protect us, selection backdrop elements

* Separate examples code, Add some selectors, fix stackblitz btn

Co-authored-by: GeoSot <geo.sotis@gmail.com>

6 files changed, 246 insertions, 28 deletions

diff --git a/site/content/docs/5.1/components/offcanvas.md b/site/content/docs/5.1/components/offcanvas.md
index 7a8cbc68a7..6ad9b6e893 100644
--- a/site/content/docs/5.1/components/offcanvas.md
+++ b/site/content/docs/5.1/components/offcanvas.md
@@ -137,9 +137,54 @@ When backdrop is set to static, the offcanvas will not close when clicking outsi
 </div>
 {{< /example >}}
 
+## Responsive
+
+<small class="d-inline-flex px-2 py-1 fw-semibold text-success bg-success bg-opacity-10 rounded-2">Added in v5.2.0</small>
+
+Responsive offcanvas classes hide content outside the viewport from a specified breakpoint and down. Above that breakpoint, the contents within will behave as usual. For example, `.offcanvas-lg` hides content in an offcanvas below the `lg` breakpoint, but shows the content above the `lg` breakpoint.
+
+<div class="bd-example">
+  <button class="btn btn-primary d-lg-none" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasResponsive" aria-controls="offcanvasResponsive">Toggle offcanvas</button>
+
+  <div class="alert alert-info d-none d-lg-block">Resize your browser to show the responsive offcanvas toggle.</div>
+
+  <div class="offcanvas-lg offcanvas-end" tabindex="-1" id="offcanvasResponsive" aria-labelledby="offcanvasResponsiveLabel">
+    <div class="offcanvas-header">
+      <h5 class="offcanvas-title" id="offcanvasResponsiveLabel">Responsive offcanvas</h5>
+      <button type="button" class="btn-close" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+    </div>
+    <div class="offcanvas-body">
+      <p class="mb-0">This is content within an <code>.offcanvas-lg</code>.</p>
+    </div>
+  </div>
+</div>
+
+```html
+<button class="btn btn-primary" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasResponsive" aria-controls="offcanvasResponsive">Toggle offcanvas</button>
+
+<div class="offcanvas-lg offcanvas-end" tabindex="-1" id="offcanvasResponsive" aria-labelledby="offcanvasResponsiveLabel">
+  <div class="offcanvas-header">
+    <h5 class="offcanvas-title" id="offcanvasResponsiveLabel">Responsive offcanvas</h5>
+    <button type="button" class="btn-close" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+  </div>
+  <div class="offcanvas-body">
+    <p class="mb-0">This is content within an <code>.offcanvas-lg</code>.</p>
+  </div>
+</div>
+```
+
+Responsive offcanvas classes are available across for each breakpoint.
+
+- `.offcanvas`
+- `.offcanvas-sm`
+- `.offcanvas-md`
+- `.offcanvas-lg`
+- `.offcanvas-xl`
+- `.offcanvas-xxl`
+
 ## Placement
 
-There's no default placement for offcanvas components, so you must add one of the modifier classes below;
+There's no default placement for offcanvas components, so you must add one of the modifier classes below.
 
 - `.offcanvas-start` places offcanvas on the left of the viewport (shown above)
 - `.offcanvas-end` places offcanvas on the right of the viewport
@@ -194,10 +239,18 @@ Try the top, right, and bottom examples out below.
 
 Since the offcanvas panel is conceptually a modal dialog, be sure to add `aria-labelledby="..."`—referencing the offcanvas title—to `.offcanvas`. Note that you don’t need to add `role="dialog"` since we already add it via JavaScript.
 
-## Sass
+## CSS
 
 ### Variables
 
+<small class="d-inline-flex px-2 py-1 fw-semibold text-success bg-success bg-opacity-10 rounded-2">Added in v5.2.0</small>
+
+As part of Bootstrap's evolving CSS variables approach, offcanvas now uses local CSS variables on `.offcanvas` for enhanced real-time customization. Values for the CSS variables are set via Sass, so Sass customization is still supported, too.
+
+{{< scss-docs name="offcanvas-css-vars" file="scss/_offcanvas.scss" >}}
+
+### Sass variables
+
 {{< scss-docs name="offcanvas-variables" file="scss/_variables.scss" >}}
 
 ## Usage
diff --git a/site/content/docs/5.1/examples/_index.md b/site/content/docs/5.1/examples/_index.md
index 3d5bfab2fb..39102f3646 100644
--- a/site/content/docs/5.1/examples/_index.md
+++ b/site/content/docs/5.1/examples/_index.md
@@ -7,30 +7,39 @@ aliases: "/examples/"
 
 {{< list-examples.inline >}}
 {{ range $entry := $.Site.Data.examples -}}
-  <h2 id="{{ $entry.category | urlize }}">{{ $entry.category }}</h2>
-  <p>{{ $entry.description }}</p>
-  {{ if eq $entry.category "RTL" -}}
-    <div class="bd-callout bd-callout-warning">
-      <p>The RTL feature is still <strong>experimental</strong> and will probably evolve according to user feedback. Spotted something or have an improvement to suggest? <a href="{{ $.Site.Params.repo }}/issues/new">Open an issue</a>, we'd love to get your insights.</p>
-    </div>
-  {{ end -}}
-
-  {{ range $i, $example := $entry.examples -}}
-    {{- $len := len $entry.examples -}}
-    {{ if (eq $i 0) }}<div class="row">{{ end }}
-      <div class="col-sm-6 col-md-4 col-xl-3 mb-3">
-        <a class="d-block" href="/docs/{{ $.Site.Params.docs_version }}/examples/{{ $example.name | urlize }}/"{{ if in $example.name "RTL" }} hreflang="ar"{{ end }}>
-          <img class="img-thumbnail mb-3" srcset="/docs/{{ $.Site.Params.docs_version }}/assets/img/examples/{{ $example.name | urlize }}.png,
-                                                  /docs/{{ $.Site.Params.docs_version }}/assets/img/examples/{{ $example.name | urlize }}@2x.png 2x"
-                                          src="/docs/{{ $.Site.Params.docs_version }}/assets/img/examples/{{ $example.name | urlize }}.png"
-                                          alt=""
-                                          width="480" height="300"
-                                          loading="lazy">
-          <h3 class="h5 mb-1">{{ $example.name }}</h3>
-        </a>
-        <p class="text-muted">{{ $example.description }}</p>
+<div class="row g-lg-5 mb-5">
+  <div class="col-lg-3">
+    <h2 id="{{ $entry.category | urlize }}">{{ $entry.category }}</h2>
+    <p>{{ $entry.description }}</p>
+    {{ if eq $entry.category "RTL" -}}
+      <div class="bd-callout bd-callout-warning small">
+        <p>
+          <strong>RTL is still experimental</strong> and will evolve with feedback. Spotted something or have an improvement to suggest?
+        </p>
+        <p><a href="{{ $.Site.Params.repo }}/issues/new">Please open an issue.</a></p>
       </div>
-    {{ if (eq (add $i 1) $len) }}</div>{{ end }}
-  {{ end -}}
+    {{ end -}}
+  </div>
+
+  <div class="col-lg-9">
+    {{ range $i, $example := $entry.examples -}}
+      {{- $len := len $entry.examples -}}
+      {{ if (eq $i 0) }}<div class="row">{{ end }}
+        <div class="col-sm-6 col-md-4 mb-3">
+          <a class="d-block" href="/docs/{{ $.Site.Params.docs_version }}/examples/{{ $example.name | urlize }}/"{{ if in $example.name "RTL" }} hreflang="ar"{{ end }}>
+            <img class="img-thumbnail mb-3" srcset="/docs/{{ $.Site.Params.docs_version }}/assets/img/examples/{{ $example.name | urlize }}.png,
+                                                    /docs/{{ $.Site.Params.docs_version }}/assets/img/examples/{{ $example.name | urlize }}@2x.png 2x"
+                                            src="/docs/{{ $.Site.Params.docs_version }}/assets/img/examples/{{ $example.name | urlize }}.png"
+                                            alt=""
+                                            width="480" height="300"
+                                            loading="lazy">
+            <h3 class="h5 mb-1">{{ $example.name }}</h3>
+          </a>
+          <p class="text-muted">{{ $example.description }}</p>
+        </div>
+      {{ if (eq (add $i 1) $len) }}</div>{{ end }}
+    {{ end -}}
+  </div>
+</div>
 {{ end -}}
 {{< /list-examples.inline >}}
diff --git a/site/content/docs/5.1/examples/navbars-offcanvas/index.html b/site/content/docs/5.1/examples/navbars-offcanvas/index.html
new file mode 100644
index 0000000000..47041fa011
--- /dev/null
+++ b/site/content/docs/5.1/examples/navbars-offcanvas/index.html
@@ -0,0 +1,147 @@
+---
+layout: examples
+title: Navbar Template
+extra_css:
+  - "navbar.css"
+---
+
+<main>
+  <nav class="navbar navbar-dark bg-dark" aria-label="Dark offcanvas navbar">
+    <div class="container-fluid">
+      <a class="navbar-brand" href="#">Dark offcanvas navbar</a>
+      <button class="navbar-toggler" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasNavbarDark" aria-controls="offcanvasNavbarDark">
+        <span class="navbar-toggler-icon"></span>
+      </button>
+      <div class="offcanvas offcanvas-end text-white bg-dark" tabindex="-1" id="offcanvasNavbarDark" aria-labelledby="offcanvasNavbarDarkLabel">
+        <div class="offcanvas-header">
+          <h5 class="offcanvas-title" id="offcanvasNavbarDarkLabel">Offcanvas</h5>
+          <button type="button" class="btn-close btn-close-white" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+        </div>
+        <div class="offcanvas-body">
+          <ul class="navbar-nav justify-content-end flex-grow-1 pe-3">
+            <li class="nav-item">
+              <a class="nav-link active" aria-current="page" href="#">Home</a>
+            </li>
+            <li class="nav-item">
+              <a class="nav-link" href="#">Link</a>
+            </li>
+            <li class="nav-item dropdown">
+              <a class="nav-link dropdown-toggle" href="#" id="offcanvasNavbarDarkDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
+                Dropdown
+              </a>
+              <ul class="dropdown-menu" aria-labelledby="offcanvasNavbarDarkDropdown">
+                <li><a class="dropdown-item" href="#">Action</a></li>
+                <li><a class="dropdown-item" href="#">Another action</a></li>
+                <li>
+                  <hr class="dropdown-divider">
+                </li>
+                <li><a class="dropdown-item" href="#">Something else here</a></li>
+              </ul>
+            </li>
+          </ul>
+          <form class="d-flex mt-3" role="search">
+            <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
+            <button class="btn btn-outline-success" type="submit">Search</button>
+          </form>
+        </div>
+      </div>
+    </div>
+  </nav>
+
+  <nav class="navbar bg-light" aria-label="Light offcanvas navbar">
+    <div class="container-fluid">
+      <a class="navbar-brand" href="#">Light offcanvas navbar</a>
+      <button class="navbar-toggler" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasNavbarLight" aria-controls="offcanvasNavbarLight">
+        <span class="navbar-toggler-icon"></span>
+      </button>
+      <div class="offcanvas offcanvas-end" tabindex="-1" id="offcanvasNavbarLight" aria-labelledby="offcanvasNavbarLightLabel">
+        <div class="offcanvas-header">
+          <h5 class="offcanvas-title" id="offcanvasNavbarLightLabel">Offcanvas</h5>
+          <button type="button" class="btn-close" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+        </div>
+        <div class="offcanvas-body">
+          <ul class="navbar-nav justify-content-end flex-grow-1 pe-3">
+            <li class="nav-item">
+              <a class="nav-link active" aria-current="page" href="#">Home</a>
+            </li>
+            <li class="nav-item">
+              <a class="nav-link" href="#">Link</a>
+            </li>
+            <li class="nav-item dropdown">
+              <a class="nav-link dropdown-toggle" href="#" id="offcanvasNavbarLightDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
+                Dropdown
+              </a>
+              <ul class="dropdown-menu" aria-labelledby="offcanvasNavbarLightDropdown">
+                <li><a class="dropdown-item" href="#">Action</a></li>
+                <li><a class="dropdown-item" href="#">Another action</a></li>
+                <li>
+                  <hr class="dropdown-divider">
+                </li>
+                <li><a class="dropdown-item" href="#">Something else here</a></li>
+              </ul>
+            </li>
+          </ul>
+          <form class="d-flex mt-3" role="search">
+            <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
+            <button class="btn btn-outline-success" type="submit">Search</button>
+          </form>
+        </div>
+      </div>
+    </div>
+  </nav>
+
+  <nav class="navbar navbar-expand-lg navbar-dark bg-dark" aria-label="Offcanvas navbar large">
+    <div class="container-fluid">
+      <a class="navbar-brand" href="#">Responsive offcanvas navbar</a>
+      <button class="navbar-toggler" type="button" data-bs-toggle="offcanvas" data-bs-target="#offcanvasNavbar2" aria-controls="offcanvasNavbar2">
+        <span class="navbar-toggler-icon"></span>
+      </button>
+      <div class="offcanvas offcanvas-end text-white bg-dark" tabindex="-1" id="offcanvasNavbar2" aria-labelledby="offcanvasNavbar2Label">
+        <div class="offcanvas-header">
+          <h5 class="offcanvas-title" id="offcanvasNavbar2Label">Offcanvas</h5>
+          <button type="button" class="btn-close btn-close-white" data-bs-dismiss="offcanvas" aria-label="Close"></button>
+        </div>
+        <div class="offcanvas-body">
+          <ul class="navbar-nav justify-content-end flex-grow-1 pe-3">
+            <li class="nav-item">
+              <a class="nav-link active" aria-current="page" href="#">Home</a>
+            </li>
+            <li class="nav-item">
+              <a class="nav-link" href="#">Link</a>
+            </li>
+            <li class="nav-item dropdown">
+              <a class="nav-link dropdown-toggle" href="#" id="offcanvasNavbarLgDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
+                Dropdown
+              </a>
+              <ul class="dropdown-menu" aria-labelledby="offcanvasNavbarLgDropdown">
+                <li><a class="dropdown-item" href="#">Action</a></li>
+                <li><a class="dropdown-item" href="#">Another action</a></li>
+                <li>
+                  <hr class="dropdown-divider">
+                </li>
+                <li><a class="dropdown-item" href="#">Something else here</a></li>
+              </ul>
+            </li>
+          </ul>
+          <form class="d-flex mt-3 mt-lg-0" role="search">
+            <input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
+            <button class="btn btn-outline-success" type="submit">Search</button>
+          </form>
+        </div>
+      </div>
+    </div>
+  </nav>
+
+  <div class="container my-5">
+    <div class="bg-light p-5 rounded">
+      <div class="col-sm-8 py-5 mx-auto">
+        <h1 class="display-5 fw-normal">Navbar with offcanvas examples</h1>
+        <p class="fs-5">This example shows how responsive offcanvas menus work within the navbar. For positioning of navbars, checkout the <a href="{{< docsref "/examples/navbar-static" >}}">top</a> and <a href="{{< docsref "/examples/navbar-fixed" >}}">fixed top</a> examples.</p>
+        <p>From the top down, you'll see a dark navbar, light navbar and a responsive navbar—each with offcanvases built in. Resize your browser window to the large breakpoint to see the toggle for the offcanvas.</p>
+        <p>
+          <a class="btn btn-primary" href="{{< docsref "/components/navbar#offcanvas" >}}" role="button">Learn more about offcanvas navbars &raquo;</a>
+        </p>
+    </div>
+    </div>
+  </div>
+</main>
diff --git a/site/content/docs/5.1/examples/navbars-offcanvas/navbar.css b/site/content/docs/5.1/examples/navbars-offcanvas/navbar.css
new file mode 100644
index 0000000000..70d209409d
--- /dev/null
+++ b/site/content/docs/5.1/examples/navbars-offcanvas/navbar.css
@@ -0,0 +1,7 @@
+body {
+  padding-bottom: 20px;
+}
+
+.navbar {
+  margin-bottom: 20px;
+}
diff --git a/site/content/docs/5.1/utilities/api.md b/site/content/docs/5.1/utilities/api.md
index 16270ad511..86cf329381 100644
--- a/site/content/docs/5.1/utilities/api.md
+++ b/site/content/docs/5.1/utilities/api.md
@@ -11,7 +11,7 @@ Bootstrap utilities are generated with our utility API and can be used to modify
 
 The `$utilities` map contains all our utilities and is later merged with your custom `$utilities` map, if present. The utility map contains a keyed list of utility groups which accept the following options:
 
-{{< bs-table "table text-start" >}}
+{{< bs-table "table table-utilities" >}}
 | Option | Type | Default&nbsp;value | Description |
 | --- | --- | --- | --- |
 | [`property`](#property) | **Required** | – | Name of the property, this can be a string or an array of strings (e.g., horizontal paddings or margins). |
diff --git a/site/content/docs/5.1/utilities/spacing.md b/site/content/docs/5.1/utilities/spacing.md
index 70fbe76945..1e5f6d32f4 100644
--- a/site/content/docs/5.1/utilities/spacing.md
+++ b/site/content/docs/5.1/utilities/spacing.md
@@ -10,7 +10,9 @@ toc: true
 
 Assign responsive-friendly `margin` or `padding` values to an element or a subset of its sides with shorthand classes. Includes support for individual properties, all properties, and vertical and horizontal properties. Classes are built from a default Sass map ranging from `.25rem` to `3rem`.
 
-Using the CSS Grid layout module? Consider using [the gap utility](#gap).
+{{< callout >}}
+**Using the CSS Grid layout module?** Consider using [the gap utility](#gap) instead.
+{{< /callout >}}
 
 ### Notation