html {
  height: 100%;
}

body {
  font-family: 'Source Sans Pro';
  padding: 100px;
  height: calc(100% - 200px);
}

body::before {
  display: block;
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  background: rgba(255,255,255,0.3);
}

#content {
  position: relative;
}

.highlight {
  line-height: 1.8;
  padding: 10px;
  background: yellow;
}

pre {
  display: inline-block;
  margin: 0;
  background: yellow;
  color: #333;
  padding: 20px;
  margin-top: 20px;
}

.button {
  text-decoration: none;
  padding: 10px;
  background: yellow;
  border: 2px solid black;
  color: #111;
}