Need help with w3schools css grid example .

[vmars316]

Hello & Thanks ;

In this example 

https://www.w3schools.com/cssref/tryit.asp?filename=trycss_grid-gap2 

The "background-color: #2196F3;"  is specified .

But where did the <div> background color come from ? 

Thanks

[dsonesuk]

They are all divs? The one you specified is the background color of class .grid-container, the second rgba(255, 255, 255, .8); is semi transparent white which is applied using

.grid-container > div which means apply styling to the top level child div containers only.

[vmars316]

Thanks dsonesuk ;

"background-color: rgba(255, 255, 255, 0.8);"  

I never knew what that extra parameter meant  ,  very cool  :  )

So I could have said #d3eafd .instead .

Thanks