Accessibility updates to Main Nav and Table of Contents

[mlama007]

These changes fix some accessibility issues:

1. Updates the semantic order of the main nav bar inside the guides so it matches the visual order going from: Open Source Guides > About > Contribute > Language. Currently, as you tab through the nav bar, it is our of order going from: About > Contribute > Language > Open Source Guides
2. Updates the Table of content to a semantic expandable button that operable by keyboard and assistive technology. Currently, this is not keyboard operable.

• Have you followed the contributing guidelines?
• Have you explained what your changes do, and why they add value to the Guides?

Please note: we will close your PR without comment if you do not check the boxes above and provide ALL requested information.

---

[Copilot]

Pull request overview

Improves navigation accessibility by aligning DOM and visual order and making the table of contents keyboard-operable.

Changes:

• Reorders guide navigation elements semantically.
• Replaces the TOC link with an accessible expandable button.
• Synchronizes TOC visual and ARIA states.

Show a summary per file

File	Description
assets/js/toc.js	Updates aria-expanded with TOC state.
assets/css/toc.scss	Resets and sizes the new button.
_layouts/article.html	Adds semantic TOC button markup and ARIA relationships.
_includes/nav.html	Aligns navigation DOM order with visual order.

Review details

Tip

Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

• Files reviewed: 4/4 changed files
• Comments generated: 0
• Review effort level: Medium