You need to be able to edit the style code in order to use this. There are a few items I included for you to edit - you can add whatever you want. To override things, you need to make a declaration for the same element(s) that you want to change, but make it more specific. Google "css specificity" if you want to - or just look at the code, the examples should sense.

Of course you could simply edit my style, but the advantage of this method is that when I update my style and you install the update, you don't have to edit it again, the override will still work.