body {
  margin: auto;
  width: 640px; 
  font-family: 'Avenir', sans-serif; 
  color: #33475b;  
  background: #8ABE53;
}

/* Centered Image Code */

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