Use themes and theme styles to increase your productivity when building an application.
About Themes
Themes are collections of templates that enable developers to define the layout and style of an entire application.
About Responsive Design and the Universal Theme
Universal Theme - 42 (Universal Theme) enables developers to build modern web applications without requiring extensive knowledge of HTML, CSS, or JavaScript
Using Theme Styles and Theme Roller
A theme style is a CSS that is added to the base CSS. Using the Theme Roller utility, developers can change the appearance of an application. Universal Theme - 42 includes theme styles.
Understanding Template Options
Template options provide developers with a declarative approach to applying different styles to components on an Oracle Application Express page.