Log in page styling issues

After activating S2member and choosing to use the s2member styling for the registration page (which worked beautifully) my log-in page suddenly had styling issues.

The box of the log-in form is too short now. Can you tell me how to correct this issue? I cant seem to find its file, looks liek maybe this is affecting it:

div#login form {
    border-radius: 5px !important;
    box-shadow: 1px 1px 2px #EEEEEE, -1px -1px 2px #EEEEEE !important;
    padding-bottom: 16px !important;
}

If I set this padding-bottom: 16px !important; to 40px its fixed, but I cant find the file to make his change in and I’m not sure if there might be a better way.

Thanks!

https://wordpress.org/plugins/s2member/