object.style.aspectRatio = "value";
<'aspect-ratio'> = auto || <ratio>
Automatically specified by the user agent.
<ratio> = <number [0,∞]> [ / <number [0,∞]> ]?
An integer or zero or more decimal digits followed by a dot (.) followed by one or more decimal digits. The first character may be preceded by a positive sign (+). The last character may be succeeded by an exponent (e or E) and an integer.