html {   
  background: url(../img/img.jpg) no-repeat center center fixed;   
  -webkit-background-size: cover;  
  -moz-background-size: cover;  
  -o-background-size: cover;  
  background-size: cover;  
}  

#credits {
  display:block;
  position: absolute;
  top: 45px;
  left: 60px;
  padding: 22px 30px;
  background: rgba(0,0,0,0.75);
  color: #fff;
  font-weight: none;
  font-family: 'Century Gothic', Helvetica, Arial, Tahoma, sans-serif;
  font-size: 18px;
}
a {
  color: #3a79cf;
}
a:hover {
  color: #5793e5;
}