{#
    Marks the nav link matching the current URL as active, and expands its
    parent section if the theme has collapsible nav sections. Works across
    completely different sidebar/nav markup because it doesn't key off a
    layout-specific class -- any link that should participate just needs a
    `data-nav-link` attribute (put it right next to `href`). Include once,
    anywhere after the nav markup exists in the DOM.

    Optional markup conventions this script honors if present, no errors
    if they're not:
      - a `data-nav-section` wrapper around a link + its submenu, expanded
        by adding the `expanded` class to both the wrapper and the
        `data-nav-submenu` element inside it.
    No context variables required.
#}
<script>
(function () {
    const normalize = (pathname) => pathname.replace(/\/$/, '').replace(/\/index\.html$/, '');
    const currentPath = normalize(window.location.pathname);
    const links = document.querySelectorAll('[data-nav-link]');

    links.forEach(link => {
        const href = link.getAttribute('href');
        if (!href) return;
        const linkPath = normalize(new URL(href, window.location.href).pathname);
        if (linkPath !== currentPath) return;

        link.classList.add('active');
        link.setAttribute('aria-current', 'page');

        const section = link.closest('[data-nav-section]');
        if (section) {
            section.classList.add('expanded');
            const submenu = section.querySelector('[data-nav-submenu]');
            if (submenu) submenu.classList.add('expanded');
        }
    });
})();
</script>