body {
  margin: 0;
  padding: 0;
}

header {
  background-color: #EBEBEB;
  display: flex;
  height: 60px;
}

header img {
  height: 40px;
  margin: 10px;
}

header ul {
  list-style-type: none;
  margin: 0;
  overflow: hidden;
  padding: 0;
}

header ul li {
  float: left;
}

header ul li a {
  color: #2C5E1A;
  display: block;
  padding: 16px;
  text-align: center;
  text-decoration: none;
}

header ul li a:hover {
  background-color: #111111;
}

#content {
  margin: auto;
  width: 1200px;
}

table {
  border-spacing: 4px;
  margin: auto;
}

td {
  border-radius: 4px;
  color: #777777;
  font-family: monospace;
  font-size: 1.25em;
  font-weight: bold;
  height: 40px;
  position: relative;
  text-align: center;
  width: 40px;
}

td a {
  display: block;
  height: 100%;
  width: 100%;
}

.not-found {
  background-color: #EBEBEB;
}

.found {
  background-color: #C1E1C1;
}