body { font-family: sans-serif; padding: 2rem; }
        .box { 
            border: 2px solid #333; 
            padding: 20px; 
            border-radius: 8px; 
            max-width: 300px;
        }
        button {
            padding: 10px 20px;
            cursor: pointer;
            background-color: #007bff;
            color: white;
            border: none;
            border-radius: 4px;
            font-size: 16px;
        }
        button:hover { background-color: #0056b3; }
        h1 { margin-top: 0; }