html {
  width: 100%;
  height: 100%;
}

body {
  width: 100%;
  height: 100%;
  margin: 0px;
  position: relative;
  background: #46c9c1;
}

div.shadow {
  position: absolute;
  max-width: 45%;
  max-height: 45%;
  top: 50%;
  left: 50%;
  overflow: visible;
}

img.logo {
  position: relative;
  max-width: 100%;
  max-height: 100%;
  margin-top: -50%;
  margin-left: -50%;
}