body {
  font-family: 'Open Sans', Arial, Helvetica, sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 24px;
  color: #222;
}

/* Header */
header {
  border-bottom: 1px solid #ccc;
  padding-bottom: 12px;
  margin-bottom: 24px;
}
header nav a {
  margin-right: 12px;
  text-decoration: none;
  color: #0077cc;
}
header .social a {
  margin-left: 6px;
}

/* Article content */
article img, article iframe {
  display: block;
  margin: 16px auto;
  max-width: 100%;
}

/* Footer */
footer {
  border-top: 1px solid #ccc;
  margin-top: 24px;
  padding-top: 12px;
  font-size: 0.9em;
  color: #555;
}