Enable overridding css classes and children in components

[loudmouth]

Hey, firstly, thanks so much for this library. As a non-JS/React developer, I found the project easy to navigate and get integrated into my site.

Now, I've reached a dilemma: I'd like to do custom styling and use custom SVG icons on all the buttons, progress bars and other components, but it seems that classes from the library itself are always applied; an example here.

Is there any way we could make classes configurable so that applying my own classes would override what's already in there? Would it also be possible to render {children}, within the button components for instance, so that I could render my own SVG-icon components?

Hope my question is understandable.