From 4673397b727680c83a7c554295371d77927e2a02 Mon Sep 17 00:00:00 2001
From: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Date: Sat, 28 Feb 2026 12:32:30 +0200
Subject: [PATCH 1/3] a11y: make the sidebar button a <button>

---
 sphinx/themes/classic/layout.html              | 4 ++--
 sphinx/themes/classic/static/classic.css.jinja | 4 +++-
 sphinx/themes/pyramid/static/epub.css.jinja    | 2 +-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/sphinx/themes/classic/layout.html b/sphinx/themes/classic/layout.html
index d2fc9270e39..bde09daf648 100644
--- a/sphinx/themes/classic/layout.html
+++ b/sphinx/themes/classic/layout.html
@@ -9,7 +9,7 @@
 {%- endblock %}
 
 {%- block sidebarextra %}{% if theme_collapsiblesidebar|tobool %}
-<div id="sidebarbutton" title="{{ _('Collapse sidebar') }}">
+<button id="sidebarbutton" title="{{ _('Collapse sidebar') }}">
 <span>{{ '»' if theme_rightsidebar|tobool else '«' }}</span>
-</div>
+</button>
 {% endif %}{% endblock %}
diff --git a/sphinx/themes/classic/static/classic.css.jinja b/sphinx/themes/classic/static/classic.css.jinja
index 24b67fa76ed..255c8d11fed 100644
--- a/sphinx/themes/classic/static/classic.css.jinja
+++ b/sphinx/themes/classic/static/classic.css.jinja
@@ -160,10 +160,12 @@ div.sphinxsidebar input {
     background-color: {{ theme_sidebarbtncolor }};
     margin-{{side}}: 0;
     color: #FFFFFF;
+    border: none;
     border-{{side}}: 1px solid {{ theme_relbarbgcolor }};
+    font: inherit;
     font-size: 1.2em;
     cursor: pointer;
-    padding-top: 1px;
+    padding: 1px 0 0;
     float: {{ 'left' if theme_rightsidebar|tobool else 'right' }};
     display: table; /* for vertically centering the <span> */
 }
diff --git a/sphinx/themes/pyramid/static/epub.css.jinja b/sphinx/themes/pyramid/static/epub.css.jinja
index cef087ced01..a6460d4cb18 100644
--- a/sphinx/themes/pyramid/static/epub.css.jinja
+++ b/sphinx/themes/pyramid/static/epub.css.jinja
@@ -142,7 +142,7 @@ div.sphinxsidebar input {
 
 {% if theme_collapsiblesidebar|tobool %}
 /* for collapsible sidebar */
-div#sidebarbutton {
+#sidebarbutton {
     background-color: {{ theme_sidebarbtncolor }};
 }
 {% endif %}

From b80109e8549cad6d4a5a020c1593a90a827c2df4 Mon Sep 17 00:00:00 2001
From: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Date: Fri, 6 Mar 2026 17:29:12 +0200
Subject: [PATCH 2/3] Add to changelog

---
 CHANGES.rst | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/CHANGES.rst b/CHANGES.rst
index 6f7279e8011..42c12e40c08 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,3 +1,29 @@
+Release 9.2.0 (in development)
+==============================
+
+Dependencies
+------------
+
+Incompatible changes
+--------------------
+
+* #14326: The sidebar button in the classic theme has changed from a ``<div>``
+  to a ``<button>``. If you have custom styles for ``div#sidebarbutton``, you
+  may need to change the filter to ``#sidebarbutton``.
+  Patch by Hugo van Kemenade
+
+Deprecated
+----------
+
+Features added
+--------------
+
+Bugs fixed
+----------
+
+Testing
+-------
+
 Release 9.1.0 (released Dec 31, 2025)
 =====================================
 

From f087e3bd8717c7496185ee08c2b5ec203284aab9 Mon Sep 17 00:00:00 2001
From: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Date: Mon, 23 Mar 2026 11:26:18 +0200
Subject: [PATCH 3/3] Add type="button"

---
 sphinx/themes/classic/layout.html | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sphinx/themes/classic/layout.html b/sphinx/themes/classic/layout.html
index bde09daf648..cf4ee2ebb74 100644
--- a/sphinx/themes/classic/layout.html
+++ b/sphinx/themes/classic/layout.html
@@ -9,7 +9,7 @@
 {%- endblock %}
 
 {%- block sidebarextra %}{% if theme_collapsiblesidebar|tobool %}
-<button id="sidebarbutton" title="{{ _('Collapse sidebar') }}">
+<button type="button" id="sidebarbutton" title="{{ _('Collapse sidebar') }}">
 <span>{{ '»' if theme_rightsidebar|tobool else '«' }}</span>
 </button>
 {% endif %}{% endblock %}