not sure why you are saying it is not responsive it looks ok to me from mobile to desktop. it might not be pixel perfect with every margin and element but it looks good enough that one should not know something is wrong in general
But I did notice two things
- the options in the popup nav are not centered between the text links and the buttons
- in desktop mode you can get the in login button to hang with different background colors when clicked not sure if you did that on purpose of what is happening with it