Font Sizes
It is recommended that the use of, relative font sizes when a widget's HTML output is styled. Relative font sizes, which are specified as a percentage of the web browser's base font size, allow the user to change the base font size in their browser to effectively magnify all of the text on the page.
Some modern web browser can scale up the text even if fixed font sizes are specified, but some browsers do not change fixed font sizes properly when the page is scaled, or scale only the text along with all other non-text content, which cannot be the user's preference.