screen.css

body {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  margin: 0;
}
a {
  color: #06f;
}
h1 {
  font-size: 2.2em;
}
h2 {
  font-size: 1.4em;
}
h2, h3, h4 {
  margin-top: 0;
}
h3, h4 {
  margin-bottom: 0.5em;
}

p, ul {
  font-size: 0.8125em;
  line-height: 1.5;
  margin: 0 0 1.5em;
}
code {
  font-size: 1.2727em;
  color: #777;
}
iframe {
  border: 0;
  overflow: hidden;
}

.container {
  margin: 0 auto;
  max-width: 46em;
  padding: 1em 0;
}

.footer {
  padding-top: 1.5em;
}
.desc {
  color: #888;
}
.intro {
  border-bottom: 1px dotted #bbb;
  padding-bottom: 1.5em;
}
.social {
  border-top: 1px dotted #bbb;
  padding-top: 1.5em;
}

/* minor responsive adjustments */

.footer {
  border-top: 1px dotted #aaa;
}
.content {
  border-bottom: 1px dotted #aaa;
  margin-bottom: 1.5em;
}

@media only screen and (min-width: 34em) {
  p, ul {
    font-size: 0.875em;
  }
  .feature:first-child,
  .info:first-child {
    border-right: 1px dotted #aaa;
  }
  .container {
    padding: 1em;
  }
  h1 {
    font-size: 1.6em;
  }
  h2 {
    font-size: 1.6em;
  }
}

@media only screen and (min-width: 54em) {
  .content {
    border: none;
    border-right: 1px dotted #aaa;
    margin-bottom: 0;
  }
  .info:first-child {
    border: none;
  }
  h1 {
    font-size: 2.0em;
  }
  h2 {
    font-size: 1.7em;
  }
}

@media only screen and (min-width: 76em) {
  .info:first-child {
    border-right: 1px dotted #aaa;
  }
  h1 {
    font-size: 2.2em;
  }
  h2 {
    font-size: 1.8em;
  }
}