Css center popup div on page

Sometime throughout our coding careers, we’ve all found ourselves frustrated with centering things in CSS (looking up how to center a div within a div on Google or Stack Overflow). It can be one of the simplest tasks to do, but can quickly become confusing as you add more elements and styles into your page.

Popup with Pure CSS - DEV Community ‍ ‍ - Dev.to 10 Oct 2019