Tab的CSS包含如下几个类，从外向里依次： (1).Ajax__tab_header: A container element that wraps all of the tabs at the top of the TabContainer. (2).ajax__tab_outer:An outer element of a tab,often used to set the left-side background image of the tab. (3).ajax__tab_inner:An inner element of a tab,often used to set the right-side image of the tab. (4).ajax__tab_tab:An element of a tab that contains the text content. (5).ajax__tab_body:A container element that wraps the area where a TabPanel is displayed. (6).ajax__tab_hover:This is applied to a tab when the mouse is hovering over. (7).ajax__tab_active:This is applied to a tab when it is the currently selected tab.
