Firefox vs Chrome  Browser CSS issues

I recently faced a issue with css float in chrome and firefox mozilla. The issue is that when i position a button in chrome, IE, safari it works fine and in firefox (mozilla) it is not working properly.

Error of Chrome browser CSS display vs Firefox Mozilla CSS display

Has you can see, same code but different outcomes. In firefox dislay there is a slight change in button #1 “Clear” and button #2 “Copy”.

How to fix CSS issues with positioning a floating element in firefox mozilla browser and chrome browser?

To fix these errors add the code highlighted in red in the image and rewrite the code. #1 code is for other browsers and #2 with the special -moz- code is for mozilla firefox browser.

@-moz-document url-prefix()