1. Better to mess with the stylesheet that applies only to your skin (YourSkinName.css or skin.css) otherwise you have more problems elsewhere
2. My advice: Get the Root Menu Items fixed first, then work on the SubMenu
3. Don't confuse the MainMenu, MainMenu_SubMenu and the ModuleTitle_Menu
4. This class affects this part (taken from the DotNetNuke Skinning Guide) :
/* Main Menu Styles */
/* Menu Container CSS Class */
.MainMenu_MenuContainer {
}
/* Menu Bar CSS Class */
.MainMenu_MenuBar {
}
/* Menu Item CSS Class */
.MainMenu_MenuItem {
}
/* Menu Icon CSS Class */
.MainMenu_MenuIcon {
}
/* SubMenu CSS Class */
.MainMenu_SubMenu {
}
/* Menu Break CSS Class */
.MainMenu_MenuBreak {
}
/* Menu Item CSS Class for mouse-over */
.MainMenu_MenuItemSel {
}
/* Menu Arrow CSS Class */
.MainMenu_MenuArrow {
}
/* Menu Root Arrow CSS Class */
.MainMenu_RootMenuArrow {
}
Those are the normal styles to control the SolPart Menu. Other elements of style need to be called in the .ascx if needed, such as Horizontal/Vertical, Separator, Effects, Level and others.
Skinning the SolPart Menu is at times difficult to master. Each Root Menu Item is actually three <td>s - the Icon part, the main part and the Arrow part.