Untitled

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8">
        <title> file </title>
        <style>
            #menu{
                background-color: #00FF00;
                width: 200px; height: 100px;
            }
            .content{
                background-color: #0000FF;
                width: 300px; height: 100px;
            }
        </style>

    </head>
    <body>
        <div id="menu"></div>
        <div class="content"></div>
    </body>
</html>