"Previous" and "Next" Buttons

"Previous" and "Next" Buttons

I have a series of pages on my website with "previous" and "next" buttons at the bottom of the page. When I preview the site in "desktop mode" I get the look I want. The previous button is to the left and the next button is to the right.



However, when I preview the site in tablet or smartphone mode the layout changes and the previous button is on top of the next button. 



How do I achieve the look of the desktop previous across all viewing platforms?  

Thanks, 

Steven