How to Develop a Responsive YB Application

i have two parts to how i develop responsive yb application. O, the first is that i am use, i call them responsive lay out containers. I can use a main area, head, or area foot, or area sidetik,. You can use sides for sideboar areas. And so i look, you know, what, what content am i really going to have in my a, in my application? and i look at it, like before, im usually do mobile first.O, we'll have like, a, think, ok, these these areas will need to be maybe positioned over, like, vertically over each other. And then on dest top, they