html {
    width:100%;
    height:100%;
}
body {
    width:100%;
    height:100%;
    margin:0px;
    position:relative;
}
img.logo {
  max-height: 90%;
  max-width: 90%;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  margin: auto;
  border: 2px solid rgb(44,44,44);
}