Okay, let's create a professional and responsive website for an engineering company. We'll start with the basic HTML structure, CSS for styling and responsiveness, and JavaScript for the tab navigation and marketplace functionality.

This sets up the basic structure, styling, and functionality. You can view the website structure and basic interactions. The design is professional, responsive, and includes the requested tabs and marketplace functionality with Font Awesome icons. Animations are kept subtle for a high-quality feel (fade-ins, hover effects, smooth transitions).