Small corrections in prject setup file.
{% extends "base.html" %}
{% load i18n %}
{% load static %}
{% block title %}{{block.super}} > {% trans 'Page not found' %}{% endblock %}
{% block css_import %}
{{block.super}}
<link rel="stylesheet" type="text/css" href="{% static 'hdalab/css/index.css' %}" />
{% endblock %}
{% block main_content %}
<div class="all-title">
<h1>{% trans 'Page not found' %}</h1>
</div>
<div class="description">
<p>{% trans 'Sorry, but the requested page could not be found.' %}</p>
</div>
{% endblock %}