Multi-tier header with dropdown menus

This component implements a multi-tier header with logo, navigation links, action buttons, and dropdown menus. The header adapts responsively for mobile and desktop layouts. Key features: - Logo, main nav links, and action buttons aligned horizontally for desktop - Hamburger menu and mobile dropdowns for mobile - Main nav links trigger dropdown submenus on hover/focus - Secondary nav links and icons in footer - Responsive styles for sizing, spacing, wrapping