Which file is critical to defining a Liferay theme's overall structure and look?

The file that is critical to defining a Liferay theme's overall structure and look is the liferay-look-and-feel.xml file. This XML configuration is essential because it allows developers to specify various attributes and settings for the theme. It helps define the fundamental visual and structural aspects of the theme, including layouts, colors, fonts, and other stylistic elements that influence how the theme is presented across the Liferay portal.

In contrast, while theme.config serves as a configuration file for theme settings, it does not directly influence the overall look and feel as comprehensively as the liferay-look-and-feel.xml. Styles.css is primarily for determining the styling and visual aspects through CSS, but it does not govern the structural definitions and configuration settings that the XML file provides. Similarly, index.jsp functions as an entry point for the theme, facilitating the rendering of content but not encapsulating the overall theme structure like the XML file does. Therefore, liferay-look-and-feel.xml stands out as the most critical file for defining the entirety of a Liferay theme’s structure and appearance.