Q:

Angular Material cdk-container and main site fixed header z-index override

I have site with fixed header in angular material with z-index of 1100.
While i have some mat-menu in my site which overlap the header with z-index:1200 and had class cdk-overlay-container (angular materiel class) which is default behavior.
To override this i just decrease the cdk-overlay-container z-index to 1000 so that it go behind the fixed header and all things ok to me.
Problem
But when i open my material dialog which uses same cdk-overlay-container and same z-index it shows my fixed header above that overlay because of its high z-index, So any idea how to achieve the above scenario by adding different class to cdk-overlay-container so that my mat-menu goes behind the fixed header but my mat-dialog above all content. 
Screen shoots
Normal scenario
https://www.screencast.com/t/XhB2szH3gZe
Problem scenario
https://www.screencast.com/t/fYrMYFEOd
I have one solution by type-script(that when dialog show lower the z-index of header) but i need some pure CSS solution.
Thanks! 

A:

I figured it out my self
Just override the z-index of cdk-overlay-container
In your style.scss 
.cdk-overlay-container{
  z-index:999; //lower then fixed header z-index so it goes behind it
}

and in your component dialog.scss
.cdk-overlay-container{
   z-index:2000 !important; //higher then fixed header z-index so it comes above
}

Cheers!

