Support for the "auto" keyword in contain-intrinsic-size lets web
sites use the last remembered size of an element (if any), which
providers for a better user experience as elements have size
containment turned on and off, e.g. through content-visibility: auto.
contain-intrinsic-size, contain intrinsic size, auto
No compat risk; all existing CSS will continue to work unchanged.
Interop risk: if web developers only use the new syntax, then content
will be sized as 0x0. They can use the usual CSS fallback syntax to
avoid this, like: contain-intrinsic-size: 100px 100px;
contain-intrinsic-size: auto 100px auto 100px;