Navigation bar and Menu in sharepoint 2010

I have a custom Mega drop down Menu need to brand it on sharepoint 2010 am I obliged to override the specific CSS of sharepoint menu or there 开发者_运维技巧is another solution if there is anaother one how can i do it cause the menu that i need is so complicated. thanks in advance please guys some help is needed here :)

Drop downs in list forms (choice or lookup fields) can be customized using InfoPath designer. In Aspx pages, masterpages and web parts, the drop down lists are normal ASP.NET DropDownList controls and can be customized via css classes as usual.