Both parent and level 1 horizontal
I would like to create a menu where both the main menu and the level-1 (there won't be any other levels) menu are horizontal. When hovering over the main menu item the level-1 items should appear as a horizontal menu below the main menu.
e.g:
[main1] [main2] [main3] [main4]
[sub1_of_main2] [sub2_of_main2]
I looked for a way to float: left; the level-1 items, but could not find one.