Custom menus!

I added a menu by using:

register_nav_menus( array( $location => $description ) );

in function.php

and added

<?php wp_nav_menu() ?> 

in header.php

yey…it worked I then went to wp-admin section and it recognized that the theme supported menus.
i created about 12 pages.
five top pages, two of those have about four drop down pages each.

My prob.
the drop down pages are not recognized as such even though they are properly placed in the wp-admin menu page. All the links display.
So to fix this:
Manually by css? thought it would be automatically done by wp. that was the whole point of indenting them?

really confused. Using chrome & inspect element i see the css that wp has created for the new custom menu.
But can’t find it to edit?
Anyone knows where it would be located?