docs/mkdocs/overrides/404.html

{#- 404 page: say what happened and offer the three useful ways out -#}
{% extends "main.html" %}

{% block content %}
  <div class="nj-404">
    <p class="nj-404__code">// error 404</p>
    <h1>This page does not exist</h1>
    <p>The page may have moved or been renamed. Try the search in the header, or start from one of these pages.</p>
    <p>
      <a href="{{ '' | url }}" class="md-button md-button--primary">Home</a>
      <a href="{{ 'features/' | url }}" class="md-button">Features</a>
      <a href="{{ 'api/basic_json/' | url }}" class="md-button">API documentation</a>
    </p>
  </div>
{% endblock %}