Jetpack comments iframe height problem

I’m working on this theme as my first trying to make a wordpress theme.

https://www.sixped.dk/wordpress
(keep in mind that it’s not done at all and it’s my first working with wordpress)

I installed the Jetpack plugin’s comment form and ran into a problem. It seems that the iframe tag’s height is set way to high and the form doesn’t collapse. The comment form is working just fine on the default theme. I really can’t figure out what I’m doing different than the default that affects the comment form.

Hope there’s somebody who can help me with this ??