body {
    background-color: #FAFAFA;
    margin: 0 auto;
    max-width: 650px;
    min-height: 100vh;
    line-height: 1.4;
    font-family: Open Sans,Arial;
    font-size: 16px;
    color: #444;
    padding: 0 10px;
    display: flex;
    flex-direction: column;
}
h1,h2,h3 {
    line-height: 1.2;
}
li p {
    margin: 0;
}
blockquote {
    border-left: 5px solid #DDD;
    padding-left: 10px;
}
code {
    background: #F4F4F4;
    border: 1px solid #DDD;
}
pre code {
    border-left: 3px solid #2B2B2B;
    display: block;
    max-width: 100%;
    overflow: auto;
    padding-left: 10px;
}
a {
    color: #07A;
    text-decoration: none;
}
header h1 {
    font-size: 2.5em;
}
footer {
    margin-top: auto;
    text-align: center;
    width: 100%;
    padding: 1em 0;
}
main {
    flex-grow: 1;
}
main img {
    display: block;
    max-width: 600px;
    max-height: 500px;
    margin: 0 auto;
}
p.sticky {
    margin-top: -1em;
}