body {
}

body {
  margin: auto;
  width: 640px; 
  background-color: rgb(0, 0, 0);
  padding: 50px;
  font-family: Arial, Helvetica, sans-serif;
  color: #fff;    
}

/* Centered Image Code */

 .center {
  height: 500px;
  display: flex;
  align-items: center;
  justify-content: center;

}

.center img {
  width: 100%;
}