<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Mobile-First Webpage</title>
    <style>
        /* Basic mobile styles */
        body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            background-color: #f4f4f4;
        }

        header {
            background-color: #333;
            color: #fff;
            padding: 10px;
            text-align: center;
        }

        nav {
            background-color: #555;
            color: #fff;
            text-align: center;
            padding: 10px;
        }

        nav a {
            color: #fff;
            text-decoration: none;
            margin: 0 10px;
        }

        section {
            padding: 20px;
            text-align: center;
        }

        footer {
            background-color: #333;
            color: #fff;
            text-align: center;
            padding: 10px;
        }

        /* Larger screens: tablet and above */
        @media (min-width: 768px) {
            header {
                padding: 20px;
            }

            nav {
                text-align: left;
                padding: 20px;
            }

            section {
                max-width: 750px;
                margin: 0 auto;
            }
        }

        /* Larger screens: desktop and above */
        @media (min-width: 1024px) {
            nav {
                padding: 30px;
            }

            section {
                max-width: 1000px;
            }
        }
    </style>
</head>
<body>
    <header>
        <h1>Welcome to My Mobile-First Webpage</h1>
    </header>

    <nav>
        <a href="#">Home</a>
        <a href="#">About</a>
        <a href="#">Services</a>
        <a href="#">Contact</a>
    </nav>

    <section>
        <h2>About Us</h2>
        <p>We are a mobile-first company focused on providing great content and services!</p>
    </section>

    <footer>
        <p>&copy; 2024 Mobile-First Webpage</p>
    </footer>
</body>
</html>