Responsive landing page with flexbox and media queries

Hi!

Congrats with new challenge. That's a cool one =)

Here is a couple of unasked advices =)

You used landmark tags, like header and footer, that's cool. But the header shouldn't contain h1 tag. You see, when the header and the footer are on top level, they are special parts of the site which remains on every page. So, in the most cases header includes logo and nav.

For the phone number and email in the footer you can use special links:

<a href="mailto:[email protected]">[email protected]</a>
<a href="tel:+1-543-123-4567">+1-543-123-4567</a>

The mailto link will open the mail agent on click, and the tel one will open the phone app if user tap it on their phone. So it's kinda good user experience to use those links and good for accessibility. Also you can wrap them into address tag.

Hope that helps =) Keep doing =)