* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  min-height: 100vh;
  background: #777;
  display: grid;
  place-items: start center;
  padding: 8px;
  font-family: Chicago, Geneva, "Helvetica Neue", Arial, sans-serif;
}

.stage {
  position: relative;
}

.hypercard {
  position: relative;
  width: 640px;
  height: 480px;
  overflow: hidden;
  background: #fff;
  transform-origin: top left;
}

#cardImage {
  position: absolute;
  inset: 0;
  width: 640px;
  height: 480px;
  image-rendering: pixelated;
  user-select: none;
}

#startButton {
  position: absolute;
  left: 251px;
  top: 248px;
  width: 99px;
  height: 93px;
  border: 0;
  padding: 0;
  background: transparent;
  cursor: default;
}

#startButton.hidden {
  display: none;
}

#scoreField {
  position: absolute;
  left: 19px;
  top: 25px;
  width: 258px;
  min-height: 20px;
  color: #000;
  font: 18px Chicago, Geneva, "Helvetica Neue", Arial, sans-serif;
  white-space: pre;
  pointer-events: none;
  display: none;
}

#scoreField.visible {
  display: block;
}

#flashLayer {
  position: absolute;
  inset: 0;
  background: #000;
  opacity: 0;
  pointer-events: none;
}

#flashLayer.flash {
  animation: flash 160ms steps(2, end);
}

@keyframes flash {
  0%,
  100% {
    opacity: 0;
  }
  50% {
    opacity: 0.18;
  }
}