contact form stoped work after changeing the css

hello every one
today i'm trying to make this contact form:
https://www.cubby.com/pl/slick-ajax-contact-form-jquery-php--origanal/_52f5017a83bb468e8dcf83d4599df786

look like this one:
https://www.cubby.com/pl/Modal+Contact+Form--origanl/_c86f6bf2c5df4a1586f84804fa276cc1

this is where i've got up to so far but the problem is that it has stoped working
when i click on send message it says

https://www.cubby.com/pl/contactform/_28ae98fcc3494e27ae02e7d3b6b0a3de

any help on how to fix this would be great many thanks