Tailwind CSS v4 Fluid Typography System Config

Create a CSS configuration and utility set for Tailwind CSS v4 that implements a fluid typography and spacing system using modern CSS `clamp()` and mathematical functions. Requirements: - Define CSS variables for font sizes (sm, base, lg, xl, 2xl, 3xl) with smooth fluid scaling based on viewport widths (min 320px, max 1440px) - Set up fluid scale ratio for high-end editorial layouts - Set up responsive fluid container padding & margins - Write out the modular Tailwind CSS v4 configuration in CSS or pure CSS utility classes - Provide a working HTML/CSS layout demo featuring responsive, non-overlapping fluid header and body typography.