fix: enhance accessibility for sidebar toggle button (#2604)

Author: sy-records

src/core/event/index.js

@@ -548,9 +548,11 @@ export function Events(Base) {
 
       // Set aria-expanded attribute
       ariaElms.forEach(toggleElm => {
+        const expanded = force ?? sidebarElm.classList.contains('show');
+        toggleElm.setAttribute('aria-expanded', expanded);
         toggleElm.setAttribute(
-          'aria-expanded',
-          force ?? sidebarElm.classList.contains('show'),
+          'aria-label',
+          expanded ? 'Hide primary navigation' : 'Show primary navigation',
         );
       });
 

src/core/render/tpl.js

@@ -43,7 +43,7 @@ export function main(config) {
     ? ''
     : `
     <button class="sidebar-toggle" tabindex="-1" title="Press \\ to toggle">
-      <div class="sidebar-toggle-button" tabindex="0" aria-label="Toggle primary navigation" aria-keyshortcuts="\\" aria-controls="__sidebar">
+      <div class="sidebar-toggle-button" tabindex="0" aria-label="Hide primary navigation" aria-keyshortcuts="Use shortcut key \\" aria-controls="__sidebar" role="button">
         <span></span><span></span><span></span>
       </div>
     </button>