Too Long; Didn't Read
The most difficult part was to position and align my interface elements (forms, graphics, controls) in the right place and to move them around as the device or at least the windows size change. This article does not pretend to be a guide to css tools but a relation of my path to get the hang of it. The Flexbox can handle most of the weight lifting for me to align and position things around. The Grid manages the wrapping and re-ordering of the elements accordingly to the media the layout is displaying on. With some media query I can re-arrange the distribution of the layout very easily.