Deleted Pages — Blog Blew Up

I started deleting pages that are no longer necessary and lost the blog…sort of. The pages I deleted did not contain blog posts. They were created as additional pages to contain static content. There may be an issue related to categories or paths. The deleted pages previously had a hierarchy (category, sub-pages, etc). I attempted to delete all at once (~170 pages). It stopped at one point, leaving many of the pages still there. At that point, the dashes at the left of each item indicating the hierarchy had disappeared. I finished deleting pages and I’m now trying to determine how to get the rest back. The blog is not recognizing the CSS file, although it’s there and uncompromised. Previously, the link to the blog went to: example.com/category/blog. Now, if I go directly to example.com/blog/index.php I get there fine (minus CSS, or at least the background elements of the page) but when I use the link in the nav, it returns a 404 error. Thoughts?