There is no law for the designer of CSS system. Only the developers who build UI have any liability to comply with the law. As long as CSS allowed them to rende

There is no law for the designer of CSS system. Only the developers who build UI have any liability to comply with the law. As long as CSS allowed them to render the required font-sizes there was no reason for them build breaks to the cascading to "comply with law", perhaps it makes it easier for developers with this feature to comply to the law, but there was no requirement to make it easy .