Formatting of embedded form is sized incorrectly by Squarespace page

We are refreshing our Squarespace website with a new template and we are having trouble with the Embed Block. We have a donate page and use the Embed Block to insert a payment form. In old website the formatting is sized correctly, but in the template the exact same code has oversized formatting. I have attached a screen shot of both forms.

Squarespace says that they can not provide any help with this and the company who provides our donate form says that it must be a problem Squarespace. So, I am not sure what to do. How do I get the form to format correctly? It appears that the styles of the Squarespace page is affecting the form. Is it possible to add code to tell the page to ignore the style of the page when displaying the form?

Our new site is not published yet and so I am not sure how to show it to the forum. 

Thank you!

15 hours ago, orchardafrica said:

Our new site is not published yet and so I am not sure how to show it to the forum

The guide How to Post a Forum Question explains how to provide a link 🙂

Here is the link to the website: https://apricots-turquoise-hkj8.squarespace.com

The password is: Orchard1 

If you click the "donate" button on the top right, there's an example of one of the forms. 

2 hours ago, Chloelamew said:

The password is

The password didn't work.

Did you use a capital "O"? I just tested it on two different accounts and the login worked for me. 

1 hour ago, Chloelamew said:

Did you use a capital "O"?

I copy and pasted the password from the post. Whatever went wrong yesterday has now passed. The password worked.