Simple.css is a classless CSS framework that provides an instant, clean design for any HTML page. The entire repository consists of a single well-crafted CSS file (simple.css) that styles all standard HTML elements—headings, paragraphs, lists, tables, forms, navigation, blockquotes, code blocks—without requiring any CSS classes. It uses CSS custom properties for theming, supports both light and dark modes via the `prefers-color-scheme` media query, employs a responsive CSS Grid layout, and includes accessibility features like focus-visible outlines and proper contrast. The repo also includes a minified version, an older v1 for backward compatibility, and a comprehensive HTML test page to demonstrate all styled elements. It is a self-contained, drop-in solution for quickly improving the appearance of any website or prototype, with no external dependencies.