Smooth Scroll

Not sure if this should be under ideas or bugs but currently when adding scroll-behavior: smooth; to the HTML of a page, it gets a red line across it (to show not valid CSS?) even though it is supported and works in most modern browsers.

Red line example

Could this get added, so there isn't a red line? Additionally, having it as an option somewhere too would be a bonus!

Thank you for this (and your other) reports!

At the moment newer CSS rules are shown with a strike through, but are exported correctly. We will add official support for these in our next release.