Nathaniel Watts updated the documentation for the rails/tailwindcss-rails repository to clarify Tailwind 4’s new approach to PostCSS integration. He revised the README using Markdown to explain that the Tailwind 4 CLI no longer supports the --postcss flag, and provided direct guidance to official Tailwind and PostCSS documentation. This work, focused on front end development and CSS, aimed to reduce misconfigurations and streamline onboarding for new users. By aligning project instructions with upstream changes, Nathaniel improved the developer experience and minimized potential support issues. The update was limited to documentation, reflecting a targeted and thorough response to evolving dependencies.