Build Online Registration Form

I need an online registration form that visitors can fill out on my existing site. It has to look clean, match my current branding, and work smoothly on mobile as well as desktop. When someone submits the form, the data should be stored in a downloadable file (CSV is fine) and an email confirmation should go both to the registrant and to me. Basic anti-spam protection such as Google reCAPTCHA is important so we keep bots away. I’m open to the underlying tech—plain HTML/PHP, a lightweight JavaScript solution, or a WordPress plugin—whatever you’re most comfortable with, as long as you can hand it over ready to embed and easy for me to tweak later.

Deliverables:
• Fully tested, responsive form page with back-end processing
• Automatic email confirmation plus admin copy
• Data saved in a CSV (or similar) that I can download anytime
• Brief setup guide showing how to add or remove fields
• One revision round after the first draft is delivered

If you have a link to something similar you’ve built, please send it along so I can get a feel for your style.