The SAPUI5 runtime loads and interprets additional resources for the control libraries during bootstrap.
The files are loaded in the following sequence:
Library bootstrap file /<context-path>/resources/<library-name>/library.js
Library style sheet file /<context-path>/resources/<library-name>/themes/<theme-name>/library.css
SAPUI5A standard CSS file that contains all styles relevant for this library. For application development tools, this file is generated automatically during the build.