(viewport) /* Default styles for desktop */ body { font-family: Arial, sans-serif; margin: 0; padding: 0; } .container { width: 960px; margin: 0 auto; padding: 20px; } /* Tablet styles */ @media screen and (max-width: 768px) { .container { width: 80%; padding: 15px; } } /* Mobile styles */ @media screen and (max-width: 480px) { .container { width: 90%; padding: 10px; } }