body {
  background: #a7b5a9;
  table { font-size: 24px; width=100%; vertical-align: top; }
  td { vertical-align: top; }
  .ack { margin: auto; padding: 10px; border: 5px red; font-size: 24px; width: 80%; text-align: center; vertical-align: middle; }
}

@media (orientation: portrait) {
  body {
    background: #c0b5a9;
    table { font-size: 32px; width=100%; vertical-align: top; }
    td { vertical-align: top; }
    .ack { margin: auto; padding: 10px; border: 5px red; font-size: 14px; width: 80%; text-align: center; vertical-align: middle;}
  }
}