The font-size-adjust CSS property sets the size of lower-case letters relative to the current font size (which defines the size of upper-case letters).
|Applies to||all elements. It also applies to ::first-letter and ::first-line.|
Choose the size of the font based only on the font-size property.
Choose the size of the font so that its lowercase letters (as determined by the x-height of the font) are the specified number times the font-size. The number specified should generally be the aspect ratio (ratio of x-height to font size) of the first choice font-family. This means that the first-choice font, when available, will appear the same size in browsers, whether or not they support font-size-adjust. 0 yields text of zero height (hidden text).