Is there a way to cache mailchimp css on wordpress?

At that point where I'm playing with load times and scores on Lighthouse, GtMetrix and the like, and am seeing problems? where external css scripts aren't being cached. For example, from mailchimp.com:

Is there a way to do this locally? With a plugin, preferably? Or is the only way to store a copy of the .css and cache that, every so often checking to see if mailchimp has changed theirs??