{% macro site_header(activePage="") %}
<h1><a href="/">{{ config.title }}</a></h1>
<nav>
  <ul>
    <li>
      <a href="/"{% if activePage == "/" %} id="nav-active-link"{% endif %}>Home</a>
    </li>

    <li>
      <a href="/posts"{% if activePage == "/posts" %} id="nav-active-link"{% endif %}>Posts</a>
    </li>

    <li>
      <a href="/about"{% if activePage == "/about/" or activePage == "/all-in-your-head/" %} id="nav-active-link"{% endif %}>About</a>
    </li>

    <li>
      <a href="/guestbook"{% if activePage == "/guestbook/" or activePage == "/guestbook/success/" or activePage == "/guestbook/nonsuccess/" %} id="nav-active-link"{% endif %}>Guestbook</a>
    </li>
  </ul>
</nav>
{% endmacro header %}