Base Apparel Challenge Solution

I started actively learning frontend development about a month ago and this challenge has been my most difficult yet.

I struggled particularly with:

1. Responsiveness.
2. Form Validation
3. Code Refactoring

I did however try to get my design close as possible to challenge objectives.

I would appreciate some feedback on my design, some advice for my problem areas and general words of wise, direction or helpful tips and resources. Thanks in advance.