Non-responsive solution (HTML/CSS/Flexbox)

Hi there! ✌️, congrats on completing this challenge. 🥳🎉

I can see that your solution is good, but there are some improvements to your solution. You are not using the main tag to wrap your main content, I recommend you that you do. For more details HERE

In your CSS code, I see that you have a small reset, that's ok, but you can improve it with the following more popular resets.

• Normalize.css
• Reset.css
• My Custom CSS Reset of Josh Comeau

Answering your last question, Its design is good, it adapts to mobile and desktop devices, You don't need media query.

Another way can be as follows:

body {
height: 100vh;
padding: 9.5rem 0rem 9.4375rem 0rem;
font-size: 15px;
background: var(--light-grey, #D5E1EF);
display: grid;
place-content: center;
}

I hope I've helped

Happy coding!