vigation">
            <span class="navbar-toggler-icon"></span>
        </button>
        <div class="collapse navbar-collapse" id="navbarToggler">
            <ul class="navbar-nav me-auto mb-2 mb-lg-0">
                <li class="nav-item"><a href="/about" class="nav-link {% if top=="abo" %}top-selected{% endif %}">About</a></li>
                <li class="nav-item"><a href="/doc" class="nav-link {% if top=="doc" %}top-selected{% endif %}">Documentation</a></li>
                <li class="nav-item"><a hr