body {
  background-color: #ececec;
}

main {
  background-color: white;
  box-shadow: 0 10px 16px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);

  min-width: 20rem;
  width: min(50vw, 50vh);
  min-height: 20rem;
  height: min(50vw, 50vh);

  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  margin: auto;

  display: flex;
  justify-content: center;
  align-items: center;
}

.logo {
  height: 100%;
  width: 100%;
  margin: auto;
}