You can use asset() function to access your css and javascript files in twig blocks as shown below.


base.html.twig


You need to place css in web/assets/css/ and js in web/assets/js/ folders.


<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>{% block title %}Welcome!{% endblock %}</title>
{% block stylesheets %}
<link href="{{ asset('assets/css/common.css') }}" rel="stylesheet" />
{% endblock %}
<link rel="icon" type="image/x-icon" href="{{ asset('favicon.ico') }}" />
</head>
<body>
{% block body %}{% endblock %}
{% block javascripts %}
<script src="{{ asset('assets/js/common.js') }}"></script>
{% endblock %}
</body>
</html>