Two-Column Layout with Full-Width Header

This implements a responsive two-column layout using Tailwind CSS utilities. It has a full-width header section, then two columns for content side-by-side on larger screens. On small screens, the columns stack vertically. The outer <div> sets a max-width for the content and centers it on the page. Inside is the header section, followed by the two columns wrapped in a flex container. The columns use Tailwind's flex-1 utility to take up equal space. At the breakpoint for small screens (640px), the columns stack using the flex-direction utility.