This ought to be really simple -- all I want to do is increase the font size of the textfields in the standard node editing form (node/123/edit). This should be a trivial tweak of a stylesheet, and I've just spent the last hour adding different bits of css to my standard theme style sheet, with no effect. Nothing is affecting the style of the fields and I can't even see (via browser Inspect Element) what stylesheet is setting the font size.
Has this changed in Drupal 7? I'm clearly missing something; can anyone offer advice?