Responsive page with Flexbox

Hi there.

I did not encounter any difficulties in particular on the challenge itself. It's general in the sense that I have a lack of practice in HTML & CSS. For example: semantics and responsiveness.

I have a big doubt precisely about the responsive. What do you think ? Does he respond to the challenge? The code can definitely be improved. I am open to opinions.

I encountered a problem on the site URL. That is, the CSS was not taken into account with Google Chrome. I tested it on Edge, Opera and Firefox. It's functional. I tested it on Google Chrome in guest mode: It works. It must probably be from my Google account.

Thank you and have a good day.