Anti-Spam Form Enhancement

I need someone to enhance my existing HTML/PHP form to block form submission spam.

This is a small job but I need a good quality, a clean and commented code tested on all devices (Windows, iOS, etc.)

Requirements:
- Implement CAPTCHA
- Add honeypot fields
- Develop validation scripts
- PHP check

Ideal Skills:
- Proficiency in HTML and PHP
- Experience with CAPTCHA and anti-spam techniques
- Strong validation script development skills