.center {
  position: fixed;
  top: 10%;
  left: 5%;
  margin-top: -10px;
  margin-left: -5px;
}

img {
  border: 1px solid #ddd;
  border-radius: 4px;
  padding: 5px;
  width: 90%;
}

img:hover {
  box-shadow: 0 0 2px 1px rgba(0, 140, 186, 0.5);
}