Need to Adjust Size of Attached Files Box

[NautiqueJeff]

1. vBulletin Version: 5.2.5
2. PHP Version: 5.6.29
3. MySQL Version: 5.5.52
4. Any Addons installed No
5. Does the issue occur in a default style? Yes
6. Does the issue occur using the English language provided? Yes
7. Error message on the screen: None
8. Browser and Browser version used: Various, including Safari, Firefox, IE
9. Did you clear the browser cache and did the error continue? Yes
10. A list of steps that can be used to recreate the issue:

I need to adjust the size of the Attached Files box that displays when a user attaches a picture or other attachment to a post.

I am running ads on the right side of the first and last posts in a thread, and when users attach files to their posts, the Attached Files box is too wide to display with the ads, and is forced down below the ads. See attached picture.

I do have my site set to a static width, so responsive width is disabled.

Is there something that I can add to css_additional.css that can set the width of the Attached Files box?

Site link: https://www.planetnautique.com