MahdiSaljoughi/app-promall ? reverse-engineered prompt

Build me a clean, modern Next.js site for a product called Promall. I want a polished homepage that feels like a real launch page, with a clear hero section, a short explanation of what the product does, a few feature highlights, and a simple call to action. Make it responsive, mobile friendly, and nicely styled with a professional look.

Use the existing app structure and keep the code simple and easy to edit. If there are any missing details, make sensible choices and fill in the gaps. I’d like the page to look good right away, with smooth spacing, readable typography, and a layout that works well out of the box. If you need to check current Next.js docs online, feel free to do that.