body {
 background-color:black; 
}

container {
  margin:0 auto;
  background-color:#ffffff;
  width:auto;
}

a {
 margin:auto; 
 width:500px;
 justify-content:center;
 align-items:center;
}

img {
 width:200px; 
 display: block;
  margin-left: auto;
  margin-right: auto;
}

.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
  width: 50%;
}