Two-tier navigation with dropdowns

This implements a responsive two-tier navigation menu with dropdowns using Tailwind CSS utility classes. It includes: - Mobile menu toggle button - Off-canvas mobile menu overlay - Top navigation with active states - Dropdown flyout menus - Company and account links - Search icon - Cart icon - Footer with sitemap sections Some key classes used: - Flexbox (flex, items-center, justify-between, etc) for layout - Box shadow, borders and rounded corners for style - Hover/focus states for interactivity - Responsive helpers like lg:hidden to hide elements on larger screens