html, body, pre, code, h1, h2, h3, h4, ul, li {
  margin: 0;
  padding: 0; }

html, body {
  font-family: 'Open Sans', sans-serif;
  font-size: 14px; }

body {
  min-width: 400px;
  overflow-x: hidden; }

h2, h3 {
  padding-top: 80px;
  margin-top: -80px; }

ul {
  list-style-type: none; }

pre {
  border: 4px solid #eee;
  padding: 10px;
  margin: 10px 0;
  overflow: hidden; }
  pre:before {
    font-family: 'Open Sans', sans-serif;
    content: 'Example:';
    font-size: 18px;
    color: #777;
    display: block;
    margin-bottom: 5px; }
  pre code {
    font-size: 14px; }

header {
  background-color: #333;
  height: 75px;
  width: 100%;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 99999;
  display: inline-block; }
  header #logo {
    margin-left: 14px;
    margin-top: 5px;
    display: inline-block; }
    header #logo a {
      font-family: monospace;
      color: white;
      text-decoration: none;
      font-weight: normal;
      opacity: 0.8;
      font-size: 40px;
      transition: opacity 0.2s ease-in-out;
      background-image: url("img/concrete-logo.png");
      background-repeat: no-repeat;
      background-size: 100px;
      background-position-y: -13px;
      height: 72px;
      display: inline-block;
      padding-left: 105px;
      box-sizing: border-box;
      padding-top: 10px; }
      header #logo a:hover {
        opacity: 1; }
  header .links {
    display: inline-block;
    float: right; }
    header .links .download {
      float: right;
      text-decoration: none;
      color: white;
      opacity: 0.7;
      font-size: 18px;
      border: 2px solid white;
      padding: 2px 10px 2px 10px;
      margin-top: 21px;
      margin-right: 18px;
      transition: opacity 0.2s ease-in-out;
      border-radius: 5px; }
      header .links .download:hover {
        opacity: 1; }
    header .links .github {
      color: white;
      font-size: 40px;
      opacity: 0.7;
      text-decoration: none;
      transition: opacity 0.2s ease-in-out;
      float: right;
      margin: 7px 20px 0 0; }
      header .links .github .text {
        margin-left: -99999px; }
      header .links .github:hover {
        opacity: 1; }
    header .links .twitter-follow-button {
      float: right;
      margin-top: 24px;
      text-decoration: none;
      margin-right: 20px;
      color: #333; }

#navigation {
  width: 270px;
  box-sizing: border-box;
  background-color: #f5f5f5;
  position: fixed;
  left: 0;
  top: 0;
  padding-top: 95px;
  height: 100%;
  overflow-y: scroll; }
  #navigation > li {
    margin-bottom: 10px; }
  #navigation li {
    margin-left: 20px; }
    #navigation li a {
      text-decoration: none;
      font-size: 16px;
      color: #444;
      opacity: 0.7;
      transition: opacity 0.2s ease-in-out; }
      #navigation li a:hover {
        opacity: 1; }

#content {
  margin-top: 75px;
  width: 100%;
  padding: 20px 20px 0 290px;
  box-sizing: border-box; }
  #content li {
    margin-left: 20px; }
  #content h2, #content h3 {
    margin: 10px 0;
    margin-top: -70px; }
  #content h2 {
    border-bottom: 3px solid #333; }
  #content p {
    font-size: 16px;
    color: #777; }
  #content a {
    text-decoration: none;
    font-size: 16px;
    color: blue; }
    #content a:hover {
      text-decoration: underline; }

#footer .grayscale {
  width: 100%;
  max-width: 1000px;
  box-sizing: border-box;
  opacity: 0.3; }

@media only screen and (max-width: 880px) {
  #navigation {
    display: none; }
  #content {
    padding-left: 0;
    margin-top: 0; }
  header {
    position: relative; }
    header .links {
      display: none; } }
