body {
    max-width: 640px;
    margin: 40px auto;
    padding: 0 20px;
    font: 15px/1.15 Helvetica, Arial, sans-serif;
    color: #222;
    background: #fafafa;
}

header {
    margin: 2rem 0;
}

h1 {
    font-size: 30px;
}

h2 {
    font-size: 30px;
    line-height: 1;
    margin: 0;
}

small {
    font-size: 15px;
    display: block;
    color: #666;
    margin-top: 0px;
    margin-bottom: 8px;
}

h3 {
    font-size: 20;
}

h4 {
    font-size: 20px;
    line-height: 1;
    margin-top: 16px;
    margin-bottom: 0px;
}

a {
    color: #0066cc;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 1.15rem auto;
    border-radius: 5px;
}