Related Posts

You'd have to do something like this:

body {
    overflow-x: hidden;
}

.wpsp-related-posts.grid-container {
    margin-left  : calc( -100vw / 2 + 100% / 2 );
    margin-right : calc( -100vw / 2 + 100% / 2 );
    max-width    : 100vw;
}

If you need the inner contents to be contained, you'll need to add a nested element inside the parent container.

It works like a charm.

You're rock Tom.

By the way, How can I add a nested element inside the parent container?

No problem!

This should work:

<div class="wpsp-related-posts grid-container">
    <div class="inside-wpsp-related-posts">

    </div>
</div>