Custom Website Contact Form (animated)

I am looking for someone who can help us code a CSS-animated FORM that we can insert into our WordPress site. We have a reference in mind and want to achieve the same effect. Please see the reference website "tux. co" and scroll down all the way until you see the button labeled: "Let's Chat". When you click it, a form gets started. (See the images attached). We want to replicate this same FORM on our site.