[Plugin: Contact Form 7] controlling checkbox layout

My goal is to control the layout of the checkboxes in the Contact7 form. The default is a mess. I’d like them to line up horizontally and vertically. Probably 3 checkbox options across and as many lines down as the options require. For example, 3 across and 4 down would provide 12 choices.

The instructions at http://contactform7.com/2009/11/21/custom-layout-for-checkboxes-and-radio-buttons/ on how to control checkboxes confuse me. Can someone please clarify?

I have two questions regarding those instructions. I think the instruction I want on the page at the above link is “Rendering checkboxes as a table”

But the illustration that accompanies it is the exact same as the previous instruction, “Rendering checkboxes as a block.” So is that second illustration an error?

2) The instructions to render checkboxes as a table say:

To render checkboxes as a table, add these lines to the CSS stylesheet in your theme like below:

span.wpcf7-list-item { display: table-row; }
span.wpcf7-list-item * { display: table-cell; }

Does it matter where in my theme’s style sheet I paste those two lines? And how can I control the layout to 3 checkboxes across unless I somehow put them in a table and cells?

Help greatly appreciated.

http://wordpress.org/extend/plugins/contact-form-7/