What to do with the sidebar?

Question

User interface

Hello. I'm building a website. There are 3 speakers on monitors, 2 speakers on tablets, but what to do with phones? Look please. I've been breaking my head for 3 days now: I don't know how to draw a sidebar on phones.

Answer 1

for example
flexbox and order to help you

Answer 2

See how it's done here on the toaster.