Can't find CSS properties for Glass Effect

I’m trying to find the CSS properties in dev tools for the glass effect, but can’t find any styles related to it at all. How do I share this with devs? There’s nothing as much as even a background blur mentioned. 
the only styles I can find are border radius and bg color, both of which I applied to my comp, and are not related to the glass effect at all. 

All help is much appreciated. 
TIA