Footer sticks to bottom of page Flat theme

Hi,

I have read various articles on how to make the footer of the “Flat” theme stick to the bottom of the page.

When there is page content that doesn’t fill up the whole page I notice the footer appears below the page content rather than forced at the bottom of the page.

Here is a guide explaining the “footer sticking”, however I cannot get this to work with the Flat theme.

https://wordimpress.com/put-a-css-sticky-footer-in-your-wordpress-theme/