problem with selected first child.....

problem with selected first child.....


I just don't get what's happening here..
http://mayacove.com/mobile/test_mobile.html

this concerns main section of the page, not top nav...

I have a hidden link @ the bottom, "back to top"...  I want this link to appear only when the top link in main section is clicked ("Languages & Software"), but try as might, everything I have tried doesn't work...

for example, for testing:
  1. $('body .wrapper:first-child section').css('border','1px solid red');
is ignored....

thought I'd try with .eq(), but don't see how you nest an element inside an element referenced with .eq() method...

thank you...