liferay default Themes file and its description

Default Themes file and its description:

File	Purpose
application.css	Contains styles having to do with components of applications. This includes the tabs, expandable trees, dialog overlays, and the results grid (i.e., Search Container). Much of the markup for these styles is created by Liferay's tag libraries.
base.css	Contains styling for standard HTML tags, such as paragraphs, headings, tables and more. This file also contains styling for some Liferay-specific page elements, such as errors, warnings, tool tips, the loading animation, and more.
dockbar.css	cssContains styling for the Dockbar, which floats at the top of the page when a user is logged in.
custom.css	This is a blank file which is loaded last. Theme developers put their Custom styles here which override styles provided by Liferay.
forms.css	Contains styling for all form elements.
layout.css	Contains styling used by layout templates.
main.css	Contains no styling, but imports the rest of the files.
navigation.css	Contains styling for the main navigation elements.
portlet.css	Contains styling for the portlet windows.
init_custom.vm	Allows you to add your own custom Velocity variables
init.vm	In conjunction with VelocityVariables.java in Liferay, sets many Velocity variables that correspond to Liferay Java objects.
navigation.vm	Implements the page navigation within the theme
portal_normal.vm	The overall template for all pages the theme implements. This file includes the other files.
portal_pop_up.vm	The overall template for any portlets which implement pop-up windows.
portlet.vm	The template for portlet windows within the theme.