@font-face {
  font-family: "Web437";
  src: url("Web437_IBM_BIOS.woff") format("woff");
}


body {
  background-color: #333;
}

body * {
  font-family: Web437;
  color: #fff;
  background-color: #50a;
  padding: 16px;
  margin: 4px;
  border: thick double #fff;
}

#main {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  display: grid;
  grid-template-columns: 1fr;

  overflow: hidden;

  box-shadow: 0px 0px 40px #00a;

  width: 480px;
  height: 320px;
}

#header {
  background-color: #000;
  height: 3em;
  border: solid #fff;
  user-select: none;
  cursor: default;
}

button {
  border: solid #fff;
  cursor: pointer;
  background-color: #00a;
  display: block;
}


button:hover {
  background-color: #00f;
}

button:active {
  background-color: #005;
  box-shadow: 0px 0px 30px #fff;
}

.secret {
  display: none;
}