style.css

body {
  padding: 0 21px;
  margin: 0 auto;
  font: 16px/2 sans-serif;
  color: #333;
  max-width: 700px;
}

h1, h2, h3 {
  color: black;
  padding-left:  13px;
  padding-right: 13px;
  border-bottom: 1px solid hsl(0,0%,88%);
}

h1 {
  font-size: 34pt;
}
h2 {
  font-size: 21pt;
  margin-top: 1.5em;
}
h2.step {
  background: url(footprint.png) no-repeat 97% 50%, hsl(205,100%,93%);
}

h3 {
  font-size: 18pt;
}

h3.goal { background: hsl(100,100%,93%); }
h3.inst { background: hsl(35 ,95%,93%); }
h3.ex { background:   hsl(55 ,90%,93%); }

h2.step,
h3.goal,
h3.inst,
h3.ex {
  border-bottom: none;
}

p {
  margin-left: 13px;
  margin-right: 13px;
}

a {
  padding: 2px 5px;
  color: hsl(200,100%,34%);
  text-decoration: none;
  background: hsl(205,100%,95%);
  border-bottom: 1px solid hsl(205,100%,87%);
  box-shadow: 0 1px hsl(205,100%,98%);
}
  a:hover {
    background: hsl(205,100%,90%);
    border-color: hsl(205,100%,83%);
    box-shadow: 0 1px hsl(205,100%,97%);
  }
  a:active {
    background: hsl(205,100%,85%);
    border-color: transparent;
    box-shadow: none;
  }

div.box {
  margin-left: 70px;
}

pre {
  margin: 0 13px;
  padding: 13px 21px;
  font-size: 13px;
  line-height: 1.75;
  color: black;
  background: hsl(205,13%,98%);
  border: 1px solid hsl(205,13%,93%);
  border-radius: 3px;
}

code {
  background: hsl(205,13%,98%);
  border: 1px solid hsl(205,13%,93%);
  padding: 0.2em;
  font-size: 0.8em;
  border-radius: 3px;
}