Preview card component challenge hub with HTML and vanilla CSS

Hello, Frontend Mentor community! This was my first challenged, and I learned a lot! To further learn more and improve my skills, I welcome any comments and suggestions on how to become a better frontend developer.

With that said, I also have some specific questions:

1. Responsiveness is honestly a tough subject for me. Do you have any tips on how to get better at this concept, or resources to share so I may improve?

2. Are there any tips for clean HTML and CSS code?

3. What tools do you use that help you in coding? For example, the Prettier extension for cleaning code or code generators like for box shadows?