Professional Responsive Website Build

I’m putting together a small, professional-looking site built purely with HTML, CSS, and vanilla JavaScript. It will have three core pages: a welcoming homepage, an about section that outlines a brief profile, and a fully working contact page.

Design & look
• Overall feel: clean, modern, and unmistakably professional—no flashy animations, just subtle transitions that keep the experience smooth.
• Palette: light and neutral tones with plenty of white space so the content stands out and remains easy on the eyes across devices.

Mobile-first responsiveness is essential; layouts should gracefully adapt from phones all the way up to large desktop screens.

Contact form requirements
The form must include:
• Name, email, and message fields
• Optional file upload (single file, common types like PDF, JPG, PNG)
• Captcha or similar mechanism to stop spam

All three parts should submit via JavaScript with basic client-side validation and a clear success/error message placeholder—I’ll hook up any server-side processing later.

Deliverables
1. Fully working front-end source code (HTML, CSS, JS) in clear folder structure
2. Read-me with quick setup notes and any external libraries (keep these lightweight and open-source only)
3. Brief usage comments within the code so I can tweak text, colours, or sections without hunting around

Once handed over I should be able to drop the files on any standard web host and have the site running immediately.