html5 and css

Hello, I just completed the QR code component challenge. I have a few questions.

• I set the 'main' container width to 350px instead of using min/max width, is it okay to do that?

• is it okay to also upload the fonts and images i used in the code to github? if not, please specify other ways i can use them

• how do i go about that rule of "Page should contain a level-one heading"?

• does my code follow best practices? what are the best practices?

Any additional feedback will be duly appreciated.

Thanks.

- Stanmancer (►__◄)