How to increase the bottom offset??

Hi everyone, earlier i have an issue about addthis share button in amp pages, which is now solved with a floating share button at the bottom of page. But due to this, the footer is being covered by the share buttons. Therefore, i was thinking to increase the bottom offset of the amp pages. But i don’t have much knowledge about that. How to do that??

The page I need help with: [log in to see the link]