artisana on "mailchimp widget alignment - where to find the file in order to edit?"

Hello!
I am trying to figure out where I can find the file where I can edit the following code for the Mailchimp subscribe Widget:

.mc_merge_var {
    margin-bottom: 0;
    margin-left: 0;
    margin-right: 0;
    margin-top: 0;
    padding-bottom: 0;
    padding-left: 0;
    padding-right: 0;
    padding-top: 0;
}

(I want to change the left padding to 22px so that the fields are centered on the widget)

When using FireBug I can see "mscf_action..."something or other but I've already looked in the Mailchimp & 2011 Extension plugin css's and no luck.

Any help or insight is very appreciated.