styles.css

* {
    font-family: 'Fira Sans', sans-serif;
    font-weight: 300;
    color: #111111;
}

main p {
    font-size: 1.1em;
    line-height: 1.2em;
}

header a {
    text-decoration: none;
    font-size: 2em;
    line-height: 2em;
}

h1, h2, h3, h4, h5, h6 { font-weight: 400; }
h1 { font-size: 1.6em; }
h2 { font-size: 1.4em; padding-top: 0.7em; }
h3 { font-size: 1.2em; padding-top: 0.6em; }
h4 { font-size: 1.0em; padding-top: 0.5em; }
h5 { font-size: 0.8em; padding-top: 0.4em; }
h6 { font-size: 0.6em; padding-top: 0.3em; }

header {
    border-bottom: 1px solid #111111;
}

footer {
    border-top: 1px solid #111111;
}

footer p {
    font-size: 0.9em;
    text-align: right;
}

body {
    margin: 0 auto;
    padding: 3em 4em 5em 4em;
    max-width: 900px;
    font-size: 1em;
    line-height: 1em;
}