style.css

body {
  max-width: 48em;
  margin: auto;
  padding: 1em 0;
}

header h1 {
  display: none;
}

h2 {
  margin-top: 1.5em;
  border-bottom: 1px solid;
}

header img {
  display: block;
  margin: auto;
}

dt {
  font-weight: bold;
  margin: 0.5em 0;
}

dd ul {
  margin: 0;
  padding: 0;
}

#sessions dt {
  margin-bottom: 0;
}

#sessions dd {
  border: 1px solid;
  margin: 0;
  padding: 10px 40px;
}

#sessions dd + dt {
  margin-top: 1em;
}

#archives li {
  list-style-type: none;
}

#archives ul > li {
  display: block; 
}
#archives ul > li > ul li { 
  display: inline-block; 
}

/**
 * color scheme
 */

.nerd {
  font-family: monospace;
  font-size: 14px;
  background-color: #111;
  color: #ccc;
}

.nerd a,
.nerd a:visited {
  color: #faa;
  text-decoration: underline;
}

.nerd a:hover {
  color: #f88;
  text-decoration: underline;
}

.nerd #sessions dt {
  color: #faa;
}

.nerd #sessions dd {
  background-color: #444;
  border-color: #966;
  color: #fff;
}

/**
 * Media queries for mobile
 */

@media only screen and (min-device-width : 320px) and (max-device-width : 640px) {
    #fork-me {
        display: none;
    }

    header img {
        max-width: 100%;
        height: auto;
    }
}