oliverdavies.uk/source/_partials/nav.twig

<nav class="navbar navbar-inverse navbar-fixed-top">
    <div class="container">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>
            <a class="navbar-brand" href="{{ site.url }}/">{{ site.title }}</a>
        </div>

        <div id="navbar" class="collapse navbar-collapse" role="navigation">
            <ul class="nav navbar-nav">
                <li class="{{ page.url == '/.' ? 'active' }}">
                    <a href="/">About</a>
                </li>

                <li class="{{ page.url == '/experience' ? 'active' }}">
                    <a href="/experience">Experience</a>
                </li>

                <li class="{{ page.url == '/testimonials' ? 'active' }}">
                    <a href="/testimonials">Testimonials</a>
                </li>

                <li class="{{ page.url == '/talks' or '/talks/' in page.url ? 'active' }}">
                    <a href="/talks">Talks</a>
                </li>

                <li class="{{ page.url == '/blog' or '/blog/' in page.url ? 'active' }}">
                    <a href="/blog">Blog</a>
                </li>

                <li class="{{ page.url == '/contact' or '/contact/' in page.url ? 'active' }}">
                    <a href="/contact">Contact</a>
                </li>
            </ul>
        </div>{# .nav-collapse #}
    </div>
</nav>