.nav {
  list-style-type: none;
  margin: 0;
  padding: 0;
  background-color: #111111;
  display: flex;
}

.nav li a {
  display: block;
  color: white;
  padding: 15px 15px 15px 15px;
  text-decoration: none;
}

.nav li a:hover {
    background-color: #333333;
}

.header {
    background-image: url("keyboard.jpg");
    background-size: cover;
    
    color: white;
    text-transform: uppercase;
    text-align: center;
}

.bolder {
  font-weight: bolder;
}