    </div>
    </div>
    <div class="header">
        <div class="wrapper">
            <h1>Flex Box and Grid are the Best!</h1>
        </div>  
    </div>
    <div class="wrapper">
        <div class="flex-box">
            <p>The best thing about Flex Box:</p>
            <div class="flex">
                <div class="box"></div>
            </div>
        </div>
    </div>
</body>
</html>