Hmmm, it seems you want to hide the urlbar when you click in the search box. Would this have the effect of allocating more space to the search box? I don't know how to do that with CSS alone. The two bars do not have a parent/child relationship and are not adjacent neighbors (''the stop and reload buttons are in between''). Perhaps someone with a more advanced understanding of CSS selectors can think of a way. I see you posted this question on userstyles.org as well ([http://forum.userstyles.org/discussion/31266/firefox-search-bar-tweaks Firefox Search Bar Tweaks - forum.userstyles.org]). That might be a good place to get an answer because it attracts advanced tweakers.

You have a sharp eye, and your observations are correct. :) Thank you.