Suggestion on how to make Protected Content look & feel closer to my website

Hi again,

I don't know if it's appropriate to ask you this, but maybe you could help me.

The Protected Content pages are not fitting with the wordpress theme I'm using. So I was wondering if you have any suggestions on how quickly change the look and feel to fit a bit better.
Here's one page so you know what I mean: http://85.139.91.106/bmw/register/
And the account details page with form elements is even worse.

I don't see any options for changing color scheme, etc... so maybe the answer is that I'll just have to style it myself.
Was just wondering if you have any suggestions, like grabbing a stylesheet from a demo site you've developed before, or something like that...

Many Thanks