How can automatic scaling be done in app

Good afternoon
I wrote a small application for myself. The question is, when I open it in the desktop, everything is ok, but as soon as I open it on the phone, part of the interface is not visible. Not scalable. How can automatic scaling be done? In the mobile version, if you can move the page to the right, then to the left, just half of the page is cut off.

worktime-[employee monitoring software]

I assume you’re using Vaadin 8, as you’re posting in the Vaadin 6, 7, 8 category? If so, this training video covers some topics related to making your app responsive: