diff --git a/src/sphinx_book_theme/assets/scripts/index.js b/src/sphinx_book_theme/assets/scripts/index.js
index 256f2a71..b094d040 100644
--- a/src/sphinx_book_theme/assets/scripts/index.js
+++ b/src/sphinx_book_theme/assets/scripts/index.js
@@ -213,32 +213,55 @@ function addBlurToButtons() {
  * Fix sidebar toggle behavior for wide screens
  * On wide screens (>= 992px), clicking the toggle should collapse the sidebar,
  * not open it as a dialog modal. The dialog behavior is only for narrow screens.
+ *
+ * Bind every matching button. When navbar_* is non-empty, pydata-sphinx-theme
+ * emits a hidden navbar .primary-toggle / .secondary-toggle earlier in the DOM
+ * than the visible article-header control; querySelector() would bind only the
+ * hidden one.
  */
 function fixSidebarToggle() {
-  const primaryToggle = document.querySelector(".primary-toggle");
   const primarySidebar = document.querySelector("#pst-primary-sidebar");
   const primaryDialog = document.querySelector("#pst-primary-sidebar-modal");
+  const secondarySidebar = document.querySelector("#pst-secondary-sidebar");
+  const secondaryDialog = document.querySelector(
+    "#pst-secondary-sidebar-modal",
+  );
 
-  // Fix primary sidebar toggle
-  if (primaryToggle && primarySidebar && primaryDialog) {
-    // Intercept clicks on the toggle button BEFORE pydata-sphinx-theme's handler
-    primaryToggle.addEventListener(
-      "click",
-      (event) => {
-        const isWideScreen = window.matchMedia("(min-width: 992px)").matches;
-
-        if (isWideScreen) {
-          // On wide screens, prevent the dialog from opening and toggle sidebar visibility instead
-          event.preventDefault();
-          event.stopImmediatePropagation();
-
-          // Toggle a class to hide/show the sidebar
-          primarySidebar.classList.toggle("pst-sidebar-hidden");
-        }
-      },
-      true,
-    ); // Use capture phase to run before PST's handler
-  }
+  const bindToggles = (toggles, sidebar, dialog) => {
+    if (!sidebar || !dialog) {
+      return;
+    }
+    toggles.forEach((toggle) => {
+      // Intercept clicks BEFORE pydata-sphinx-theme's handler
+      toggle.addEventListener(
+        "click",
+        (event) => {
+          const isWideScreen = window.matchMedia("(min-width: 992px)").matches;
+
+          if (isWideScreen) {
+            // On wide screens, prevent the dialog from opening and toggle sidebar visibility instead
+            event.preventDefault();
+            event.stopImmediatePropagation();
+
+            // Toggle a class to hide/show the sidebar
+            sidebar.classList.toggle("pst-sidebar-hidden");
+          }
+        },
+        true,
+      ); // Use capture phase to run before PST's handler
+    });
+  };
+
+  bindToggles(
+    document.querySelectorAll(".primary-toggle"),
+    primarySidebar,
+    primaryDialog,
+  );
+  bindToggles(
+    document.querySelectorAll(".secondary-toggle"),
+    secondarySidebar,
+    secondaryDialog,
+  );
 }
 
 /**
diff --git a/tests/js/test_fix_sidebar_toggle.mjs b/tests/js/test_fix_sidebar_toggle.mjs
new file mode 100644
index 00000000..555b6f59
--- /dev/null
+++ b/tests/js/test_fix_sidebar_toggle.mjs
@@ -0,0 +1,218 @@
+/**
+ * Unit tests for fixSidebarToggle (executablebooks/sphinx-book-theme#935).
+ *
+ * When navbar_* is non-empty, pydata-sphinx-theme emits a hidden navbar
+ * .primary-toggle earlier in the DOM than the visible article-header button.
+ * querySelector('.primary-toggle') binds only the first (hidden) node.
+ */
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { createRequire } from "node:module";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { test } from "node:test";
+
+const require = createRequire(import.meta.url);
+const { JSDOM } = require("jsdom");
+
+const ROOT = path.resolve(
+  path.dirname(fileURLToPath(import.meta.url)),
+  "../..",
+);
+const INDEX_JS = path.join(
+  ROOT,
+  "src/sphinx_book_theme/assets/scripts/index.js",
+);
+
+function extractFixSidebarToggleSource() {
+  const src = readFileSync(INDEX_JS, "utf8");
+  const start = src.indexOf("function fixSidebarToggle");
+  if (start < 0) {
+    throw new Error("function fixSidebarToggle not found in index.js");
+  }
+  let depth = 0;
+  let started = false;
+  let end = start;
+  for (let i = start; i < src.length; i++) {
+    if (src[i] === "{") {
+      depth += 1;
+      started = true;
+    } else if (src[i] === "}") {
+      depth -= 1;
+      if (started && depth === 0) {
+        end = i + 1;
+        break;
+      }
+    }
+  }
+  return src.slice(start, end);
+}
+
+const FIX_SIDEBAR_TOGGLE_SRC = extractFixSidebarToggleSource();
+
+function stubMatchMedia(window, isWide) {
+  window.matchMedia = (query) => ({
+    matches: Boolean(isWide && /min-width:\s*992px/.test(query)),
+    media: query,
+    addListener() {},
+    removeListener() {},
+    addEventListener() {},
+    removeEventListener() {},
+    dispatchEvent() {
+      return false;
+    },
+  });
+}
+
+function setupDom({ navbarToggles = true, isWide = true } = {}) {
+  const navbar = navbarToggles
+    ? `
+      <header class="bd-header">
+        <button class="pst-navbar-icon sidebar-toggle primary-toggle" type="button">navbar primary</button>
+        <button class="pst-navbar-icon sidebar-toggle secondary-toggle" type="button">navbar secondary</button>
+      </header>`
+    : `<header class="bd-header"></header>`;
+
+  const dom = new JSDOM(
+    `<!DOCTYPE html>
+    <html>
+      <body>
+        ${navbar}
+        <div class="bd-header-article">
+          <div class="header-article-item">
+            <button class="sidebar-toggle primary-toggle btn btn-sm" type="button">article primary</button>
+          </div>
+          <div class="header-article-item">
+            <button class="sidebar-toggle secondary-toggle btn btn-sm" type="button">article secondary</button>
+          </div>
+        </div>
+        <aside id="pst-primary-sidebar"></aside>
+        <aside id="pst-secondary-sidebar"></aside>
+        <dialog id="pst-primary-sidebar-modal"></dialog>
+        <dialog id="pst-secondary-sidebar-modal"></dialog>
+      </body>
+    </html>`,
+    {
+      pretendToBeVisual: true,
+      url: "https://example.test/",
+      runScripts: "dangerously",
+    },
+  );
+
+  stubMatchMedia(dom.window, isWide);
+  dom.window.eval(`${FIX_SIDEBAR_TOGGLE_SRC}; fixSidebarToggle();`);
+  return dom;
+}
+
+function click(window, el) {
+  const event = new window.MouseEvent("click", {
+    bubbles: true,
+    cancelable: true,
+  });
+  el.dispatchEvent(event);
+  return event;
+}
+
+test("(A) navbar_center + desktop: article-header primary-toggle hides primary sidebar", () => {
+  const dom = setupDom({ navbarToggles: true, isWide: true });
+  const { document } = dom.window;
+  const toggles = document.querySelectorAll(".primary-toggle");
+  assert.equal(
+    toggles.length,
+    2,
+    "navbar toggle must precede article-header toggle",
+  );
+  assert.ok(toggles[0].closest(".bd-header"));
+  assert.ok(toggles[1].closest(".bd-header-article"));
+
+  const articleToggle = document.querySelector(
+    ".bd-header-article .primary-toggle",
+  );
+  const sidebar = document.querySelector("#pst-primary-sidebar");
+  assert.equal(sidebar.classList.contains("pst-sidebar-hidden"), false);
+
+  click(dom.window, articleToggle);
+  assert.equal(
+    sidebar.classList.contains("pst-sidebar-hidden"),
+    true,
+    "visible article-header Toggle Sidebar must toggle the primary sidebar",
+  );
+
+  click(dom.window, articleToggle);
+  assert.equal(
+    sidebar.classList.contains("pst-sidebar-hidden"),
+    false,
+    "a second click must show the primary sidebar again",
+  );
+
+  const navbarToggle = document.querySelector(".bd-header .primary-toggle");
+  click(dom.window, navbarToggle);
+  assert.equal(
+    sidebar.classList.contains("pst-sidebar-hidden"),
+    true,
+    "each .primary-toggle is bound, including the earlier navbar button",
+  );
+});
+
+test("(B) navbar_center + desktop: article-header secondary-toggle hides secondary sidebar", () => {
+  const dom = setupDom({ navbarToggles: true, isWide: true });
+  const { document } = dom.window;
+  const toggles = document.querySelectorAll(".secondary-toggle");
+  assert.equal(toggles.length, 2);
+  assert.ok(toggles[0].closest(".bd-header"));
+  assert.ok(toggles[1].closest(".bd-header-article"));
+
+  const articleToggle = document.querySelector(
+    ".bd-header-article .secondary-toggle",
+  );
+  const sidebar = document.querySelector("#pst-secondary-sidebar");
+  assert.equal(sidebar.classList.contains("pst-sidebar-hidden"), false);
+
+  click(dom.window, articleToggle);
+  assert.equal(
+    sidebar.classList.contains("pst-sidebar-hidden"),
+    true,
+    "visible article-header secondary toggle must toggle the secondary sidebar",
+  );
+});
+
+test("(C) empty navbar_*: only article-header primary-toggle still works on desktop", () => {
+  const dom = setupDom({ navbarToggles: false, isWide: true });
+  const { document } = dom.window;
+  assert.equal(document.querySelectorAll(".primary-toggle").length, 1);
+  assert.ok(document.querySelector(".bd-header-article .primary-toggle"));
+
+  const articleToggle = document.querySelector(
+    ".bd-header-article .primary-toggle",
+  );
+  const sidebar = document.querySelector("#pst-primary-sidebar");
+  click(dom.window, articleToggle);
+  assert.equal(sidebar.classList.contains("pst-sidebar-hidden"), true);
+});
+
+test("(D) narrow/mobile: article-header primary-toggle does not intercept the dialog path", () => {
+  const dom = setupDom({ navbarToggles: true, isWide: false });
+  const { document } = dom.window;
+  const articleToggle = document.querySelector(
+    ".bd-header-article .primary-toggle",
+  );
+  const sidebar = document.querySelector("#pst-primary-sidebar");
+
+  let bubbleReached = false;
+  articleToggle.addEventListener("click", () => {
+    bubbleReached = true;
+  });
+
+  const event = click(dom.window, articleToggle);
+  assert.equal(
+    sidebar.classList.contains("pst-sidebar-hidden"),
+    false,
+    "narrow viewport must not collapse via pst-sidebar-hidden",
+  );
+  assert.equal(event.defaultPrevented, false);
+  assert.equal(
+    bubbleReached,
+    true,
+    "capture handler must not stopImmediatePropagation so PST can open the dialog",
+  );
+});