There could be an HTML error somewhere in your code/text (a missing tag, or an extra tag, etc). When I try it, it seems to works fine. I would double check all of your code inside of your widgets, as well as the post/page content on that page to make sure there’s nothing missing. Until then you can add width: 100%
directly to the code around line 1349 and it would provide a temporary fix until you figure out what the actual cause is –
.home-feature-bg .featuredpage .page,
.home-feature-bg .featuredpost .post