modify form field sizes

I would like to find out how to change the size of the form windows? I need to make the "Company name and Address" fields smaller. I see it in firebug that it is set to "41"
,but I can not find which page to edit it on?

Can anyone give some ides, please?

includes/templates/YOUR_CUSTOM_TEMPLATE_NAME/templates/tpl_modules_create_account.php around line 39 for Company.

Thank you. The only one I could not find is the "country". Any idea?

Create a special stylesheet for the page and include things like the following:

eg includes/templates/YOUR_TEMPLATE/css/mypage.css

input#org_name {width:22em; margin:0.15em 0em;}
input#org_reg {width:11em; margin:0.15em 0em;}
input#org_address {width:22em; margin:0.15em 0em;}
input#org_address2 {width:22em; margin:0.15em 0em;}
input#org_city {width:22em; margin:0.15em 0em;}
input#org_state {width:22em; margin:0.15em 0em;}
input#org_postcode {width:11em; margin:0.15em 0em;}
input#org_country {width:22em; margin:0.15em 0em;}