The <ratio> CSS data type, used for describing aspect ratios in media queries, denotes the proportion between two unitless values. It is a strictly positive <integer> followed by a slash (‘/’, Unicode U+002F SOLIDUS) and a second strictly positive <integer>. There may be spaces before and after the solidus.
Examples
Ratio
Usage
4/3
Traditional TV format in the 20th century.
16/9
Modern, ‘widescreen’, TV format.
185/100 = 91/50(non-integer dividends and divisors are not allowed)
The most common movie format since the 1960s.
239/100(non-integer dividends and divisors are not allowed)
