body {
  background-color: #FFFFCC;
  font-family: sans-serif;
  max-width: 960px;
  margin-left: auto;
  margin-right: auto;
  width:100%;
  height:100%;
}

.sidebar {
  height: 100%;
  width: 160px;
  position: fixed;
  z-index: 1;
  top: 0;
  left: 0;
  background-color: #111;
  overflow-x: hidden;
  padding-top: 20px;
}

.sidebar a {
  display: block;
}

.buttons {
  text-align: center;
  display: block;
  margin-left: auto;
}

.button {
  cursor: pointer;
  width: 80px;
}

h1 {
  text-align: center;
  color: grey;
}

ul {
  list-style: none;
}

.boxes {
  width: 480px;
  margin: 2em auto 0;
}

.box {
  background: grey;
  border-radius: 4px;
  width: 150px;
  height: 150px;
  float: left;
  margin-right: 15px;
  margin-bottom: 15px;
  padding: 1.75em;
  cursor: pointer;
  box-sizing: border-box;
  transition: 0.2s ease;
  background-size: 100px 100px;
  background-repeat: no-repeat;
  background-position: center center;
}

.box:nth-child(3n) {
  margin-right: 0;
}

.boxHuman {
  background-color: #FFA000;
  background-image: url('img/o.svg');
  transition: 0.2s ease;
  pointer-events: none;
}

.boxComputer {
  background-color: #3688C3;
  background-image: url('img/x.svg');
  transition: 0.2s ease;
  pointer-events: none;
}