2 buttons styles on site

HI, I have 2 buttons styles on my site which are conflicting. I have some button that are in columns which are full width – here is an example (see private). These buttons are from the advanced style settings.

I want to create a second button style for rounded edged buttons that will be everywhere else on the website. But dont know the best approach to doing this. the second screenshot is how I want the second button style.