:root {
  color-scheme: dark;
  --bg: #000000;
  --halftone-dot: #ff2d55;
  --paper: #ffffff;
  --halftone-tile: 22px;
  --halftone-radius: 5px;
  --dos-blue: #0000a8;
  --dos-cyan: #00a8a8;
  --dos-bright-cyan: #00ffff;
  --dos-yellow: #ffff00;
  --dos-white: #ffffff;
  --dos-black: #000000;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--dos-white);
  font-family: "Courier New", monospace;
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
  touch-action: manipulation;
}

/* Keeps the iOS status-bar / notch strip black in the installed PWA instead
   of showing the white splash behind it. Zero height everywhere else. */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: env(safe-area-inset-top, 0px);
  background: #000;
  z-index: 9999;
  pointer-events: none;
}

#output {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  display: block;
  object-fit: cover;
  background: var(--bg);
}

#webcam {
  display: none;
}

/* Title screen: drifting red Ben-Day dots on white, with a color-cycling title. */

.overlay {
  position: fixed;
  inset: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  overflow: hidden;
  background-color: var(--paper);
}

/* Oversized tiled dot layer that scrolls diagonally from the bottom left to
   the top right. Two identical dot grids, the second shifted half a tile on
   both axes, give the offset (brick) rows of a real halftone screen rather
   than a plain square grid. Both grids share the tile size, so translating
   the layer by exactly one tile loops seamlessly. */
.overlay::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  pointer-events: none;
  background-color: var(--paper);
  background-image: radial-gradient(
      circle,
      var(--halftone-dot) var(--halftone-radius),
      transparent calc(var(--halftone-radius) + 1px)
    ),
    radial-gradient(
      circle,
      var(--halftone-dot) var(--halftone-radius),
      transparent calc(var(--halftone-radius) + 1px)
    );
  background-size: var(--halftone-tile) var(--halftone-tile);
  background-position: 0 0,
    calc(var(--halftone-tile) / 2) calc(var(--halftone-tile) / 2);
  animation: halftone-drift 9s linear infinite;
}

@keyframes halftone-drift {
  from {
    transform: translate3d(0, 0, 0);
  }
  to {
    transform: translate3d(var(--halftone-tile), calc(-1 * var(--halftone-tile)), 0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .overlay::before {
    animation: none;
  }
}

.overlay.hidden {
  display: none;
}

.overlay.dimmed {
  opacity: 0;
  pointer-events: none;
}

.overlay-content {
  position: relative;
  z-index: 1;
  text-align: center;
}

.brand {
  margin: 0;
  font-family: "Irish Grover", "Courier New", cursive;
  font-size: clamp(2.75rem, 12vw, 7rem);
  font-weight: 400;
  line-height: 1;
  color: var(--halftone-dot);
  -webkit-text-stroke: 6px var(--dos-black);
  paint-order: stroke fill;
  text-shadow: 7px 7px 0 var(--dos-black);
}

/* Sits below the title and is the only thing that changes on click (prompt ->
   "Requesting camera..." -> any error), so it is positioned out of flow: its
   text can change length without nudging the title. */
.status-line {
  position: absolute;
  left: 50%;
  top: calc(100% + 2rem);
  transform: translateX(-50%);
  margin: 0;
  white-space: nowrap;
  font-size: 0.9rem;
  font-weight: bold;
  color: var(--dos-black);
  background: var(--dos-yellow);
  padding: 0.35rem 0.7rem;
  border: 2px solid var(--dos-black);
}

.status-line.error {
  white-space: normal;
  max-width: 80vw;
  color: var(--dos-white);
  background: #a80000;
}

/* Panels: TuiCSS window/fieldset, kept close to the stock DOS-blue look. */

.tui-window.tui-panel {
  display: none;
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 50;
  width: min(94vw, 24rem);
  max-height: 88vh;
  overflow-y: auto;
  background-color: var(--dos-blue);
  color: var(--dos-white);
}

.tui-window.tui-panel.active {
  display: block;
}

.tui-panel .tui-fieldset {
  border: 6px double var(--dos-white);
  background-color: inherit;
  padding: 10px;
}

/* Turn the window legend into a stock cyan DOS title bar. */
.tui-panel .tui-fieldset > legend {
  display: block;
  width: 100%;
  margin: 0;
  padding: 2px 0;
  background-color: var(--dos-cyan);
  color: var(--dos-black);
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.tui-panel .tui-fieldset-button {
  color: var(--dos-white);
  background-color: var(--dos-cyan);
  font-weight: bold;
}

.tui-panel .tui-fieldset-button:active {
  color: var(--dos-bright-cyan) !important;
}

.panel-body {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  padding-top: 0.7rem;
}

.button-row {
  display: flex;
  gap: 0.6rem;
}

.tui-panel .tui-button {
  padding: 3px 14px;
  box-shadow: 3px 3px var(--dos-black);
  font-weight: bold;
}

.tui-panel .tui-button:active {
  box-shadow: none !important;
}

.tui-panel .tui-button:disabled,
.tui-panel .tui-button.disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.tui-panel .tui-input-fieldset {
  padding: 8px 6px;
  background-color: inherit;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.tui-panel .tui-input-fieldset > legend {
  color: var(--dos-yellow);
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0 0.3rem;
}

.tui-panel .tui-checkbox {
  color: var(--dos-white);
  padding-left: 28px;
}

.range-field {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.range-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.5rem;
  font-size: 0.78rem;
  color: var(--dos-white);
}

.range-value {
  color: var(--dos-yellow);
  font-weight: bold;
  font-size: 0.78rem;
  white-space: nowrap;
}

.range-value::before {
  content: "[";
}

.range-value::after {
  content: "]";
}

/* DOS trackbar: blocky cyan scrollbar-style slider with a square handle. */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 20px;
  margin: 2px 0;
  background-color: var(--dos-cyan);
  background-image: url("https://cdn.jsdelivr.net/npm/tuicss@2.1.2/dist/images/scroll-cyan.png");
  background-repeat: repeat;
  border: 2px solid var(--dos-black);
  cursor: pointer;
}

input[type="range"]:focus {
  outline: 2px dotted var(--dos-yellow);
  outline-offset: 2px;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: 16px;
  background: transparent;
  border: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  margin-top: 0;
  background-color: var(--dos-bright-cyan);
  border: 2px solid var(--dos-black);
  border-radius: 0;
  box-shadow: inset -2px -2px 0 rgba(0, 0, 0, 0.35), inset 2px 2px 0 rgba(255, 255, 255, 0.5);
}

input[type="range"]::-moz-range-track {
  height: 16px;
  background: transparent;
  border: none;
}

input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  background-color: var(--dos-bright-cyan);
  border: 2px solid var(--dos-black);
  border-radius: 0;
  box-shadow: inset -2px -2px 0 rgba(0, 0, 0, 0.35), inset 2px 2px 0 rgba(255, 255, 255, 0.5);
}

.stats {
  margin: 0;
  padding: 0.5rem;
  background-color: var(--dos-black);
  color: var(--dos-bright-cyan);
  font-family: "Courier New", monospace;
  font-size: 0.72rem;
  line-height: 1.4;
  white-space: pre;
  overflow-x: auto;
}

.qr-body {
  align-items: center;
  text-align: center;
}

.qr-canvas {
  width: 220px;
  height: 220px;
  image-rendering: pixelated;
  background-color: var(--paper);
  border: 2px solid var(--dos-black);
}

.qr-url {
  margin: 0;
  font-size: 0.8rem;
  font-weight: bold;
  color: var(--dos-yellow);
  word-break: break-all;
}

.qr-body .tui-button {
  align-self: center;
}