How to make an infinite addition of fields on the button?

Question

css

Hello!
A question.
I have a page with input made another form under the spoiler, but when you click on the button, they go out an infinite number of times (well, or at least 10) here is the HTML
code

spoiler

https://jsfiddle.net/sg1aa4td/2/

Answer 1

a little "mess"
see
https://jsfiddle.net/rt6xvf7y/

Answer 2

quick...
https://jsfiddle.net/dbunt1tled/b323ykhc/