Editting Pagination

So when you use the html code <!–nextpage–> it creates a button for you that links to the next page of my blog posts. I went in and edited the css div through the editor to try and change the size of the button but nothing is changing.

http://www.streamsurge.org/10-basketball-players-that-never-failed-to-wow-you/

Originally, I wanted to link the blue next button directly to the smaller next page button, but I have no idea how to do that. I figured instead I would just try to edit the button myself, but even after editing the code and inspecting the element, nothing is happening.