<head>
    <link rel= "stylesheet" type= "text/css" href= "{{ url_for('static',filename='styles/header.css') }}">
</head>
<header class="site-header">
    <div class="site-identity">
        <h1><a href="/">Online Kanban board</a></h1>
    </div>  
    <nav class="site-navigation">
        <ul class="nav">
        {% if not current_user.is_authenticated %}
            <li><a href="/login">Login</a></li> 
            <li><a href="/signup">Sign up</a></li> 
        {% endif %}
        {% if current_user.is_authenticated %}
            <li><a href="/logout">Logout</a></li> 
        {% endif %}
        </ul>
    </nav>
</header>