html, body {
  margin: 0px;
  font-size: 4.5em;
  font-family: 'Open Sans', sans-serif;
  height: 100%;
  background-color: #414ef8;
  color: #fff;
}

@media (min-width: 300px) {
    html { font-size: 70%; }
}

@media (min-width: 500px) {
    html { font-size: 80%; }
}

@media (min-width: 700px) {
    html { font-size: 120%; }
}

@media (min-width: 1200px) {
    html { font-size: 200%; }
}

table, tr, td {
  width: 100%;
  height: 100%;
  text-align: center;
  vertical-align: middle;
}