Recently, a new css feature has been merged to css spec regarding custom highlight :-)
github.com/w3c/csswg-dr...
github.com
[css-highlight-1][css-pseudo-4] Add ::highlight(*) by DevSDK · Pull Request #14301 · w3c/csswg-drafts
[css-highlight-1], [css-pseudo-4] add ::highlight(*) selector as per #9091
