body {
  margin: 0;
  padding-top: 50px;
  font-family: Arial, sans-serif;
  background: url('https://pixabay.com/static/uploads/photo/2014/06/16/23/39/black-370118_960_720.png') no-repeat center center fixed;
  background-size: cover;
  color:white ;
}

nav {
  background: rgba(51, 51, 51, 0.8);
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
}

nav a {
  color: white;
  padding: 14px 20px;
  display: inline-block;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.3s;
}

nav a:hover {
  background: rgba(85, 85, 85, 0.8);
}

.content {
  padding: 20px;
}