Uku – Full-Width Template – doesn’t get full-width?!

Hi,

here is the example: https://www.nsonic.de/blog/full-width-test/

This is a page where i set the template to full-width.
As you can see: The Text is starting left on the page (still a border to the left browser-edge, is OK) but then it didn’t flow to the very right. It seems, that it is still at about 900px … only difference to Default-Template or Without Sidebar is where the text starts on the page

What i like to see is getting the “full width” (maybe with a little bit of a edge) – Why? I like to insert a shortcode of a plugin (posts-grid, gallery, etc.) and currently they all are getting only about 900px for their own presentation…

any idea to get it into full-width? Thanks a lot