W3.CSS is a modern CSS framework with built-in responsiveness. Smaller and faster than any other CSS frameworks. Easier to learn, and easier to use than any other CSS frameworks. Better cross-browser compatibility than any other CSS frameworks. Uses standard CSS only (No jQuery or JavaScript library). Supports modern responsive mobile first design by default. Provides CSS equality for all browsers: Chrome, Firefox, Edge, IE, Safari, Opera. Provides CSS equality for all devices: desktop, laptop, tablet, and mobile. Speeds up and simplifies web development.