.container-fluid{
  text-align: center;
}

header{
  text-align:center;
}


.box{
  padding-top: 100px;
}

#img{
  background-color:white;
  color: white;
}

body {
  background-image: url("http://img.freepik.com/free-vector/black-and-green-radar_1063-116.jpg?size=338&ext=jpg");
  background-repeat: no-repeat;
  background-size: cover;
   -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  
  
}
h1{
  font-size: 30px;
  color: white;
  text-align: center;
}



#city{
  font-size: 30px;
  color: red;
}

#temperature{
  font-size: 30px;
  color: red;
}

#description{
  font-size: 30px;
  color: red;
}

#button{
  font-size: 30px;
  color: blue;
}