Explain expectations for content which shifts while fully obscured by other content (i.e. covered by a fixed position z-index overlay)
mmocny opened this issue · comments
Michal Mocny commented
Ideally, layout shifts would not be reported for content which shifted while within viewport but still completely obscured and not visible to users. (For example, when covered by a full screen overlay)
However, this is not currently the case, due to complexity and expense of computing if shifted nodes were actually fully obscured. I have gotten questions about this and found that there is no direct documentation in the spec, or the explainer.
Should we add a note to non-normative section or just to the Limitations section of explainer?