I guess this is one of times where it's better to just do it in a test site than think you can write it on the fly, coffee or not.
here is full tested level 1, 2, and 3 width change css:
ul#cssmw > li > ul.level-1 > li > a {
width:200px;
}
ul#cssmw > li > ul.level-1 > li > ul.level-2 {
left:60px;
}
ul#cssmw > li > ul.level-1 > li > ul.level-2 > li > a {
width:200px;
}
ul#cssmw > li > ul.level-1 > li > ul.level-2 > li > ul.level-2 {
left:60px;
}
ul#cssmw > li > ul.level-1 > li > ul.level-2 > li > ul.level-2 > li > a {
width: 200px;
}