How do I center the entire form?

Here is an example where I centered all the inputs in a form:
http://gravity.chrishajer.com/contact-us/

Here is the CSS I used to do it:

[css]
body #gform_wrapper_32 {
width:598px;
border:1px solid #C2C2C2;
padding:5px;
}
body #gform_wrapper_32 .gform_heading span.gform_description {
color:red;
display:block;
text-align:center;
}
body #gform_wrapper_32 .gform_body ul li.gfield {
text-align:center;
}
body #gform_wrapper_32 .gform_footer input[type='submit']  {
color:#FFFFFF;
background:red;
float:none;
display:block;
width:140px;
margin:0 auto;
}

Your CSS may be different depending on the type of fields in your form. This CSS applies only to form 32, so be sure to change that to your form ID if you choose to implement something like this.

There is a global way to make changes to the Gravity Forms styles. Add the rules to your theme's stylesheet and make them specific enough that they override all other rules (or use the !important declaration to ensure this new rule is honored.)

If you'd like help styling your form, please post a link to it with an explanation of how we can help make the changes you want to see.