body { background-color: #2F4059; height: 100%;     height: 100%;
  overflow: hidden; }

.logo {
  display: flex;            /* new */
  align-items: center;      /* new */
  justify-content: center;  /* new */
  width: 100%;
  height: 100vh;
  background-size: cover;
  text-align: center;
}

.flex-center { align-items: center; justify-content: center; flex-direction: column; }



.outer-container {
  position : absolute;
  display: table;
  width: 100%;
  height: 100%;
}

.inner-container {
  display: table-cell;
  vertical-align: middle;
  text-align: center;
}

.centered-content {
  display: inline-block;
}