Widely available
This feature is well established and works across many devices and browser versions.
Chrome
Edge
Firefox
Safari
ar-autoaspect-ratio: auto;ar-1/1aspect-ratio: 1;ar-1/2aspect-ratio: 1 / 2;ar-2/1aspect-ratio: 2;ar-2/3aspect-ratio: 2 / 3;ar-3/2aspect-ratio: 3 / 2;ar-3/4aspect-ratio: 3 / 4;ar-4/3aspect-ratio: 4 / 3;ar-4/5aspect-ratio: 4 / 5;ar-5/4aspect-ratio: 5 / 4;ar-5/7aspect-ratio: 5 / 7;ar-7/5aspect-ratio: 7 / 5;ar-9/16aspect-ratio: 9 / 16;ar-16/9aspect-ratio: 16 / 9;ar-21/9aspect-ratio: 21 / 9;ar-9/21aspect-ratio: 9 / 21;Media Queries
Prefix a class with a breakpoint to apply it from that width up.
Pseudo Classes
Prefix a class with a state to apply it only while that state matches.