Responsive Huddle landing page created with CSS Flexbox

Hii everyone, this is the 15th challenge I have tried to recreate. I'm so happy about how it turned out, but I think I could further improve in writing cleaner code.

It would be helpful for my future growth if you could point me in the right direction. For example, I'm interested in potentially better solutions for this challenge. In which area do I need to improve, and what do you recommend that I should implement? What are some best practices that I haven't got right?

Thanks for your attention and all the future feedback.