Accessibility: the header search icon link now has an accessible name (aria-label "Search" + role "button"; decorative SVG hidden). Fixes the Lighthouse "Links must have discernible text" audit. Applied at runtime too, so headers already saved in the Site Editor are covered.
Mobile menu: restored the theme's overlay colors (WordPress 7.1 started painting the open mobile menu white with white links); submenus now collapse into an accordion (tap the arrow to expand; the current page's branch opens automatically) and use the same font size as the top-level items
Accessibility: the header search icon's accessible name is now also added server-side when the header was customized in the Site Editor, so PageSpeed's "Links must have discernible text" audit passes on the initial HTML