Locking Global Site Footer to bottom of screen

Site URL: http://www.studio6f.com/

I am *renovating* our site right now, and for some reason I cannot figure out how to lock the footer to the bottom of the screen. I understand that this will probably need some specific CSS code, however nothing I've found online seems to work. It is less noticeable on the home page, but for instance on the 'about' and 'contact' pages, the footer has crept up. Help!

It looks like you solved?

If you look at the 'contact' page, you'll see that the issue is not solved. Most of the pages have enough content to push the footer nearly to the bottom, but it is inconsistent from the home page to the 'about' page to the 'contact' page. The 'contact' page is especially bad, the others don't bother me honestly. 

Add to Contact Page Settings > Advanced > Header

<style>
  main#page {
    min-height: 90vh;
}
</style>