Adding class="hidden" is not hiding code snippets

[danny-andrews]

I followed the instructions here to add a library, but the code snippet is not hidden in the outputted html.

index.html:

<script src="https://unpkg.com/sprintf-js@1.1.2/dist/sprintf.min.js"></script>
    <script>
      window.klipse_settings = {
        selector_eval_js: '.klipse-eval-js',
      };
    </script>
    <script async src="https://storage.googleapis.com/app.klipse.tech/plugin_prod/js/klipse_plugin.min.js"></script>

my-blog-post.md:

<pre class="hidden"><code class="hidden klipse-eval-js" data-external-libs="https://unpkg.com/sprintf-js@1.1.2/dist/sprintf.min.js">
sprintf
</code></pre>

Result:

[viebel]

You need to add the CSS for the class hidden:

.hidden {
    display: none;
}