<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="ie=edge">
        <title>{% block title %}{% endblock %}</title>

        <!-- Bootstrap core CSS -->
        <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
        <!-- jQuery + Bootstrap JS, for stuff like modals to work -->
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
        <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
        <!-- Custom styles css -->
        <link href="static/styles.css" type="text/css" rel="stylesheet">
        <!-- Custom js -->
        <link href="static/app.js" type="text/css" rel="stylesheet">
    </head>
    <body>
        {% block body %}
        {% endblock %}
    </body>
</html>
<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="ie=edge">
        <title>{% block title %}{% endblock %}</title>

        <!-- Bootstrap core CSS -->
        <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
        <!-- jQuery + Bootstrap JS, for stuff like modals to work -->
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
        <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
        <!-- Custom styles css -->
        <link href="{{url_for('static', filename='styles.css')}}" type="text/css" rel="stylesheet">
        <!-- Custom js -->
        <link href="static/app.js" type="text/css" rel="stylesheet">
    </head>
    <body>
        {% block body %}
        {% endblock %}
    </body>
</html>
Use url_for to render static files to avoid bug with url converters
Use url_for to render static files to avoid bug with url converters
