I just signed up with authorize.net and plan to use their SIM. In reading the implementation guide, they say you can include a stylesheet in the header to include things like logo, etc.. Are there any guidelines to follow for this stylesheet, i.e. size and positioning of images... I know there are tutorials for creating good twitter pages, but does anything like that exist for an authorize.net SIM hosted payment page?
I used this guide to stylish the SIM payment form:
BTW, I would recommend you to change the layout of this form, but no very heavy, because your customer must understand that he/she left your site and now make a payment on secure authorize.ner site.