By default, themes are based on the _styled theme, which provides only basic styling of portlets. If you open the build.xml file in your theme’s directory using the Build Application Configuration Editor, you see the following code:
The theme.parent property determines the theme your theme inherits its styling from. In addition to the _styled theme, you can choose to inherit from the _unstyled theme, which contains no styling. This makes more work for you, but offers full flexibility to design your CSS files from scratch.
You can also use the default Liferay theme Classic as a parent theme. You’ll start with a look and feel that’s already smooth and works well. But since so much is already done for you, there’s less flexibility when building your design. It’s a compromise between creating a theme as quickly as possible versus having full control of the result. It’s your choice, and another example of the flexibility Liferay offers.
Want to learn how to import resources with your theme? We’ll discuss how you can do this in the next section.