If you are looking to lengthen the input text field for EXTRA FIELDS, this is not in the css.
in file, skin1/modules/Extra_Fields/product_modify.tpl
find:
Code:
<td><input type="text" name="efields[{$ef.fieldid}]" size="24" value="{if $ef.is_value eq 'Y'}{$ef.field_value|escape:"html"}{else}{$ef.value|escape:"html"}{/if}" /></td>
and make size="100" (or whatever you want)