I found that it was much easier to work with bootstrap if you just download the long form css version. Although it is a larger file, it is more straightforward since you can see all of the css for each element and then customize accordingly. The point of bootstrap is that it provides some nice defaults for you to work with for all elements, so you can build simple apps quickly. It is the role of the developer to customize the defaults when they do not suit the needs of the project. It honestly isn't that hard if you know a decent amount of css to quickly customize the classes to suit your own needs.