Dhtmlx responsiveness help

Hello.
I am having a minor problem. I am trying to use this library and I don’t know how to make my app responsive. I notice this when I accidentally resize my browsers size/width and I notice that the
layout is not resizing. How can I make it responsive?

Please, try to set the sizes of the layout-s container in percents.

How about sidebar? How can the right container responsive.
It is not working to me.

Bear with me. Can you provide a simple script/code so that I can figure the way around.

How to size using percentage? I tried using width: "90%" not working. Did I missed something? I cannot find this on the documentation.

You need to define the size in percents to the container where the layout is placed in.
https://dhtmlx.com/docs/products/dhtmlxLayout/samples/01_init/03_fullscreen.html