Is Flexbox being used for all sites nowadays since being accessible from mobile devices seems important for most websites? When would we not want to use it?

I would like to talk more about Positioning on a Grid.

Why is having HTML elements overlap useful?

still dont quite get positioning

I am still a bit confused about position: absolute and position: relative, and the coordinate system

Why do we want to position the ancestor using position: relative and use position: absolute for the child? 

still a bit confused on positioning since it seemed like a lot all at once

Can you talk more about position:relative? I'm confused about how to use it.

"could you explain why you set 
main {
  flex: 1 1 auto;
}
instead of 
main {
  flex: 1 0 auto;
}
when you only want main to grow and not shrink?"

the readings are making a lot more sense now! / The reading was pretty straightforward, I enjoyed it!

No questions at the moment-- I think some of the concepts might just take practice.