renderTemplate() renders the twig file without any CSS I've set up the routing for a specific URL in my plugin to trigger the actionIndex controller method. I after logging a message to the Craft logs, I want to return the rendered twig file as the view, which is supposed to look just like an empty Control Panel page. Pretty simple in theory.

Everything in the twig file seems to render just fine (text &amp; images) except for the CSS.

Controller: Controller.php

class Controller extends \craft\web\Controller
{
    public function actionIndex(){

        Craft::info("hello!", __METHOD__);

        return Craft::$app-&gt;getView()-&gt;renderTemplate('plugin/done');
    }
}


Template: done.twig

{% extends "_layouts/cp" %}
{% set title = "Manual Sync"|t('plugin') %}

{% block content %}
    &lt;p&gt;Manual Sync Done.&lt;/p&gt;
{% endblock %}


I've attached a screenshot of the elements that are rendered on the page.


Hopefully that is enough for someone to help bounce some ideas around with me. Any advice and suggestions would be greatly appreciated!
I sincerely appreciate the responses!
I've since resolved this issue, below is the changed code. My controller was extending the Craft web controller (\craft\web\Controller) which has its own renderTemplate() method that I switched to, which fetches the Control Panel assets I wanted for styling the page.

The template twig file remains identical as is above.

(Modified) Controller: Controller.php

class Controller extends \craft\web\Controller
{
    public function actionIndex(){

        Craft::info("hello!", __METHOD__);

        return $this-&gt;renderTemplate('plugin/done');
    }
}


This did the trick for what I wanted. Thanks again!