JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
    <head>
        <title>
            Задание 2. Блок с тенью
        </title>
        <link type = "text/css" rel = "stylesheet" href = "style.css">
        <!--[if IE]>
            <script src = "http://html5shiv.googlecode.com/svn/trunk/html5.js"></script>
        <![endif]-->
    </head>
    <body>
        <h1>
            Заголовок
        </h1>
        <div>
            Содержание блока
        </div>
    </body>
</html>

CSS

*
{
    margin: 0;
    padding: 0;
    font-size: 100%;
}
html,
body
{
    padding: 20px;
}
html
{
    font: 125% arial, sans-serif;
}
body
{
    font-size: 50%; /* 10px */
}
h1,
div
{
    background-color: #C9E39C;
    padding: 5px 10px;
    max-width: 250px;
}
h1
{
    font-size: 1.6em;
    display: inline-block;
    border-radius: 5px 5px 0 0;
    border-top: 1px solid #ACD283;
    border-left: 1px solid #ACD283;
    border-right: 1px solid #ACD283;
    margin-bottom: -1px;
    box-shadow: 0 -2px 5px #CFCCD3;
}
div
{
    font-size: 1.4em;
    min-height: 100px;
    border-radius: 0 0 5px 5px;
    border: 1px solid #ACD283;
    box-shadow: 0 0 7px #CFCCD3;
}