Sunnyside challenge using CSS Grid, Flexbox and BEM methodology

The hardest thing for me was: 1.- Changing the color of the social media icons on the footer. 2.- Create the border in mobile navigation(I didn't know how to create a triangle with CSS) :p

What I'm not too sure about:

• The header image loses quality on very large devices, it was the biggest problem and I couldn't find a solution.
• I set the max width to 1400px so the site wouldn't lose the layout of the challenge.
• If I used the BEM methodology correctly.

What should I do to not lose image quality on very large devices? What should I improve on for the next project?

I loved the challenge, I learned many things and reinforced previous knowledge.