* {
  margin: 0;
  padding: 0;
}

nav {
  display: flex;
  justify-content: center;
}

nav ul { list-style: none; }

nav > ul > li {
  display: inline-block;
  float: left;
  box-sizing: border-box;
  width: 180px;
  margin-top: 50px;
}

nav a {
  text-decoration: none;
  background-color: #2d3f56;
  display: block;
  color: white;
  width: 180px;
  padding: 13px 0;
  text-align: center;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 14px;
  box-sizing: border-box;
}

nav a:hover { background-color: #f93e3e; }

nav > ul > li > a { transform: skew(20deg); }

nav > ul > li > a > span {
  display: block;
  transform: skew(-20deg);
}

.hidden li:nth-child(odd) a {
  transform: skew(-25deg);
  background-image: linear-gradient(185deg, rgba(0,0,0,0.5), #2d3f56 30%)
}

.hidden li:nth-child(even) a {
  transform: skew(25deg);
  background-image: linear-gradient(175deg, rgba(0,0,0,0.5), #2d3f56 30%)
}

.hidden li:nth-child(even) span {
  display: block;
  transform: skew(-25deg);
}

.hidden li:nth-child(odd) span {
  display: block;
  transform: skew(25deg);
}

.hidden li:nth-child(even) a {
  position: relative;
  left: 5px;
  width: 200px;
}

.hidden li:nth-child(odd) a {
  position: relative;
  left: -5px;
  width: 200px;
}

.hidden { display: none; }

.hidden li > a { position: absolute; }

footer {
  position: fixed;
  left: 0;
  bottom: 0;
  padding: 10px;
  background: #2d3f56;
  color: white;
  width: 100%;
}

footer > p {
  text-align: center;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
}