No footer in what you showed or what I gave you.
Can you show it live? Give us a URL?
Or... If you mean that when the answer appears it occupies space and so shoves down whatever is below it, there's an easy fix: So long as the answer isn't longer than one line, just put an (Non-Breaking SPace) into the <div> that gets the answer. That character will be the same height as the answer and so when the answer appears, stuff below it shouldn't move. Or or or... Again, showing it to us live would be best way for us to see the problem.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.