[css-pseudo] Properties applicable to Highlights

[Crissov]

The css-pseudo ED currently says:

The highlight pseudo-elements can only be styled by a limited set of properties that do not affect layout.

…

ISSUE 1
 Are there any other properties that should be included here?

Since none of the background sub-properties affect layout, it seems logical to allow them all, not just background-color.

Unlike border, outline and its sub-properties do not affect layout and should therefore be supported as well.

Iʼm pretty sure that most fill and stroke properties also qualify; theyʼre limited to stroke-color, fill-color and stroke-width at the moment.

[fantasai]

background other than background-color are dependent on the size of the box also, which is why they aren't allowed: the size of the box is not defined

[Crissov]

Okay, then at least “that so not affect layout” would need some rewording (unless my English skills are failing me here).

[Dalzhim]

Is there a way that we could allow for complex underlining styles such as the squiggles often displayed by code editors? As an example, could the outline-* family of properties be leveraged in this regard?

[fantasai]

@Dalzhim Yes, see https://www.w3.org/TR/css-text-decor-4/

[fantasai]

@Crissov That information was in the source code because it seemed like TMI for the spec, but since you requested it's now in the spec. Lmk if that works for you.