Modular Paralaxx with Full Width

Hello, maybe someone can help me. I'm grav beginner just trying something with the CMS. I would like to see a Modular page where a Paralaxx effect can be seen. The Paralaxx effect I present as follows.

<style>
.parallax {
/ The image used /
background-image: url("http://****.jpeg");

/* Set a specific height */
height: 500px; 

/* Create the parallax scrolling effect */
background-attachment: fixed;
background-position: center;
background-repeat: no-repeat;
background-size: cover;

}
</style>

<!-- Container element -->
<div class="parallax">
Hallo
</div>

I get to see the Paralaxx effect, but not the full width.

Maybe someone has an idea. Thank you