Main Menu narrows and wraps on Donation page

See two attached files. This website is built on a bootstrap-enabled template with a 1349 px canvas. The standard Joom Donation menu links to a form that looks like it is a perfect 940px wide. However, when I navigate to the standard Donation form, it always narrows my main menu and wrecks the uniformity of the website. I tried the plugin embedded in a regular article with the same results.

Please fix the form page so it does not affect the width or wrap of the main menu.

wildfarmlands.org

Thanks,

Ed Seaman