Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The :-moz-first-node CSS pseudo-class is a Mozilla extension that represents any element that is the first child node of some other element. It differs from :first-child because it does not match a first-child element with (non-whitespace) text before it.
Note: Any whitespace at the start of an element is ignored for the determination of :-moz-first-node.